Diamine-containing, tetra-substituted piperazine compounds having identical 1- and 4-substituents

ABSTRACT

There is provided compounds having the formula of structure I: 
                         
wherein the groups —C(R 8 )(CH 2 ) v CH(R 9 )(CH 2 ) y -Q and —C(R 8 )(CH 2 ) v CH(R 9 )(CH 2 ) y -J are the same, and R 1a , R 1b , R 2a , R 2b , R 8 , R 9 , J, Q, W, X, L 2 , v and y have meanings given in the description. The use of such compounds in the treatment of a condition responsive to changes in melanocortin receptor function in a human or non-human mammal (e.g. male sexual dysfunction, female sexual dysfunction, an eating disorder, above optimal body weight, obesity, below-optimal body weight or cachexia) is also described.

This application claims the benefit of U.S. Provisional Application No.60/886, 434,filed Jan. 24, 2007; U.S. patent application Ser. No.11/464,053, filed Aug. 11, 2006; U.S. patent application Ser. No.11/464,069; U.S. Provisional Application No. 60/822,135; PCTInternational Application No. PCT/US2006/031472; and PCT InternationalApplication No. PCT/US2006/031474, each of which is incorporated byreference in its entirety.

The present invention relates to tetra-substituted piperazine compoundswith diamine groups that bind to one or more melanocortin receptors andare agonists, antagonists, mixed agonist-antagonists, inverse agonist orantagonists of inverse agonists with respect to one or more melanocortinreceptors, and use thereof for the treatment of metabolic, immune,infection-related and other melanocortin receptor-mediated disorders,including treatment of obesity and related energy homeostasis disordersand diseases.

A family of melanocortin receptor types and subtypes have beenidentified, including melanocortin-1 receptors (MC1-R) expressed onnormal human melanocytes and melanoma cells, melanocortin-2 receptors(MC2-R) for ACTH (adrenocorticotropin) expressed in cells of the adrenalgland, melanocortin-3 and melanocortin-4 receptors (MC3-R and MC4-R),expressed primarily in cells in the hypothalamus, mid-brain andbrainstem, and melanocortin-5 receptors (MC5-R), expressed in a widedistribution of tissues.

In general, compounds specific for MC1-R are believed to be useful fortreatment of melanoma. Compounds specific for MC3-R or MC4-R arebelieved to be useful in regulation of energy homeostasis, including useas agents for attenuating food intake and body weight gain, for use intreatment of anorexia, as a weight gain aid, for treatment of obesity,and treatment of other food intake and metabolism-related purposes.Compounds specific for MC3-R and MC4-R can further be used as agents fortreatment of sexual dysfunction, including male erectile dysfunction andfemale sexual dysfunction. Other melanocortin receptor-specificcompounds, such as MCR-1 agonists, can be used as tanning agents toincrease melanin production in the skin, acting as chemo-preventiveagents against harmful effects of UV solar radiation. Compounds specificfor MCR-1 and MCR-3 may further be useful in regulation of inflammatoryprocesses.

There is a significant need for compounds with high specificity fordiscrete melanocortin receptors, as well as for compounds that areeither agonists or antagonists for specific melanocortin receptors. Highaffinity compounds for melanocortin receptors can be used to exploitvaried physiological responses associated with the melanocortinreceptors, either as agonists or antagonists. In addition, melanocortinreceptors have an effect on the activity of various cytokines, and highaffinity compounds for melanocortin receptors can be used to regulatecytokine activity.

There are piperazine and piperidine compounds known, such as thosedisclosed in WO 02/070511 (Bristol-Myers Squibb Company), WO 02/059095(Eli Lilly and Company), and WO 00/74679 (Merck & Co., Inc.), assertedto be specific for melanocortin or related receptors. However, ingeneral such compounds have at most two functional substituted groups,have relatively poor affinity and specificity, and are not suitable foruse as a drug compound. There is a significant need for compounds withhigh specificity for discrete receptors, such as melanocortin and otherreceptors, as well as compounds that are agonists or antagonists forsuch receptors. High affinity compounds for such receptors can be usedto exploit varied physiological responses associated with the receptors,either as agonists or antagonists. There is thus a need for compoundsthat are more selective, including higher affinity and specificity, andin particular for compounds that have at least three or fourbiologically active substituted groups. This invention addresses thatneed.

WO 02/085925,“Melanocortin Receptor Ligands”, to The Proctor & GambleCompany, discloses ketopiperazine structures and methods of synthesisthereof, but does not disclose piperazine structures, piperazinestructures with four or more substituted groups, methods to synthesizepiperazine structures, methods to synthesize piperazine structures withfour or more substituted groups, or methods to synthesize optically purestructures, and further does not disclose structures with a singlesubstituent group that is a single D-Phe or D-Nal residue, or aderivative or homolog thereof, optionally with an amine capping group.

Commonly owned of U.S. patent application Ser. No. 10/837,519,publishedas Publication No. US 2004/0224957 A1,discloses piperazine compoundsspecific for one or more melanocortin receptors, but does not disclosepiperazine compounds with four substituted groups where one substitutedgroup includes a diamine heteroatom unit with at least one cationiccenter, hydrogen bond donor or hydrogen bond acceptor, and the remainingthree substituted groups each include a ring structure.

The present application claims priority from commonly-ownedinternational patent application no. PCT/US06/31472 (published as WO2007/021990). That application discloses, for the first time, a numberof specific tetra-substituted piperazine compounds, wherein thesubstituents on both N-atoms of the piperazine ring are identical.

With respect to certain objects, methods, synthetic schemes, utilities,applications, definitions, protocols and other disclosures, thisapplication is related to U.S. patent application Ser. No.10/762,079,entitled “Piperazine Melanocortin-Specific Compounds”, filedon Jan. 21, 2004 and International Application No.PCT/US02/25574,International Publication No. WO 03/013571, entitled“Peptidomimetics of Biologically Active Metallopeptides”, filed on Aug.12, 2002; and the specifications of each of the foregoing areincorporated herein by reference as if set forth in full.

There remains a significant need for compounds specific for MC4-R fortreatment of conditions relating to regulation of energy homeostasis,including use as agents for attenuating food intake and body weightgain, for treatment of obesity, and treatment of other food intake andmetabolism-related purposes.

According to the present invention, there is provided a compound havingthe formula of structure I:

or an enantiomer, stereoisomer or diastereoisomer thereof, or apharmaceutically acceptable salt thereof,wherein

-   one or two of R^(1a), R^(1b), R^(2a), and R^(2b) are independently a    C₁ to C₆ aliphatic linear or branched chain and the remaining of    R^(1a), R^(1b), R^(2a), and R^(2b) are hydrogen, provided that at    least one of R^(1a) and R^(1b) and at least one of R^(2a) and R^(2b)    are hydrogen;-   or one of R^(1a), R^(1b), R^(2a), and R^(2b) are

and the remaining of R^(1a), R^(1b), R^(2a), and R^(2b) are hydrogen;

or R^(1a) and R^(1b) together form ═O and one of R^(2a) and R^(2b) is aC₁ to C₆ aliphatic linear or branched chain,

and the remaining of R^(2a) and R^(2b) is hydrogen;

-   y is in each instance an independent index value from 0 to 5;-   W is a diamine heteroatom unit with at least one cationic center,    hydrogen bond donor or hydrogen bond acceptor;-   L² is a bond or (CH₂)_(z);-   z is an index value from 1 to 6;-   X is CH₂, C═O or C═S;-   the groups —C(R⁸)(CH₂)_(v)CH(R⁹)(CH₂)_(y)-Q and    —C(R⁸)(CH₂)_(v)CH(R⁹)(CH₂)_(y)-J are the same and, in those groups,    -   R⁸ is H or ═O;    -   R⁹ is hydrogen or N(R^(10a))R^(10b);    -   R^(10a) and R^(10b) are independently hydrogen, acetyl, methyl,        ethyl, propyl, isopropyl, butyl, pentyl, hexyl, isobutyl,        benzyl, benzoyl, hexanoyl, propionyl, butanoyl, pentanoyl,        heptanoyl, cyclopropyl, cyclopropylmethyl, cyclobutyl,        cyclobutylmethyl, cyclohexyl, cyclohexylmethyl, or polyethylene        glycol;    -   v is an index value from 0 to 2;and    -   Q and J are the same and represent an aromatic carbocyclic ring        selected from the group consisting of phenyl, substituted        phenyl, naphthyl and substituted naphthyl; wherein the carbon        atoms marked with an asterisk can have any stereochemical        configuration.

Where polyethylene glycol is present, it may have a formula molecularweight of between 100 and 50,000.

Compounds of structure I that may be mentioned include those in which R⁸is ═O.

In the compound of structure I, Q may be:

where R^(3a), R^(3b) and R^(3c) are optional ring substituents, and whenone or more are present, are the same or different and independentlyhydroxyl, halogen, alkyl, —O-alkyl, aryl, or —O-aryl.

In one aspect, at least one of R^(3a), R^(3b) or R^(3c) is —CH₃ or—O—CH₃. In another aspect, at least one of R^(3a), R^(3b) or R^(3c) is—Cl or —CF₃.

In the compound of structure I, W may include an amine, amide, alcohol,carboxylic acid, ether, ester, or urea. Thus in one aspect W is

where R⁴ is

-   -   NH,    -   O, provided that R⁵ comprises a diamine,    -   CH₂, provided that R⁵ comprises a diamine,    -   C₆H₅, provided that R⁵ comprises a diamine,    -   N(—CH₂)_(z), where N(CH₂)_(z) together with R⁵ forms a ring,    -   N(—(CH₂)_(y)-CH₃),    -   NH—C(═O),    -   NH—C(═O)—NH, provided that R⁵ does not comprise an N,    -   C(═O), provided that R⁵ comprises a diamine,    -   C(═O)—NH,    -   C(═O)-O, provided that R⁵ comprises a diamine, or    -   O—C(═O), provided that R⁵ comprises a diamine;        R⁵ is    -   NH₂, provided that R⁴ comprises one N,    -   hydroxyl, provided that R⁴ comprises a diamine,    -   CH₃, provided that R⁴ comprises a diamine,    -   NH—(CH₂)_(z) where NH—(CH₂)_(z) together with R⁴ forms a ring,    -   NH—(CH₂)_(y)-CH₃,    -   N(—(CH₂)_(y)-CH₃)₂,    -   NH—(CH₂)_(z)-NH₂,    -   NH—(CH₂)_(z)-NH—(CH₂)_(y)-CH₃,    -   NH—(CH₂))_(z)-N—((CH₂)_(y)-CH₃)₂,    -   N(—(CH₂)_(y)-CH₃)—(CH₂)_(z)-NH(CH₂)_(y)-CH₃,    -   N(—(CH₂)_(y)-CH₃)—(CH₂)_(z)-N((CH₂)_(y)-CH3)₂,    -   NH—C(═O)—(CH₂)_(y)-NH₂,    -   O—(CH₂)_(y)-CH₃, provided that R⁴ comprises a diamine,    -   SO₂—NH₂,    -   SO₂—NH—(CH₂)_(y)-CH₃,    -   SO₂—N(—(CH₂)_(y)-CH₃)₂,    -   SO₂—(CH₂)_(y)-CH₃, provided that R⁴ comprises a diamine,

where none, one or more of positions 1 to 5 are a heteroatom selectedfrom N for position 1 and S, O or NH for positions 2 to 5, provided thatonly one N is present if R⁴ comprises an N, no N is present if R⁴comprises a diamine and otherwise R⁵ comprises a diamine,

where none, one or two of positions 1 to 5 are a heteroatom selectedfrom N for position 1 and for the position to which R⁶ is bound if suchposition does not comprise C, and otherwise S, O or NH, provided that R⁵including R⁶ comprises only one N if R⁴ comprises an N, no N is presentif R⁴ comprises a diamine and otherwise R⁵ including R⁶ comprises adiamine,

where at least one bond between adjacent ring atoms is a double bond,and none or one or more of positions 1 to 5 are a heteroatom selectedfrom N for position 1 and any double bond position and otherwise S, O orNH for positions 2 to 5, provided that not more than one position is Sor O, and further provided that only one N is present if R⁴ comprises anN, no N is present if R⁴ comprises a diamine and otherwise R⁵ comprisesa diamine,

where at least one bond between adjacent ring atoms is a double bond,and one or more of positions 1 to 5 are optionally a heteroatom selectedfrom N for position 1, the position to which R⁶ is bound if suchposition does not comprise C, and any double bond position and otherwiseS, O or NH for positions 2 to 5, provided that not more than oneposition is S or O, and further provided that R⁵ including R⁶ comprisesonly one N if R⁴ comprises an N, no N is present if R⁴ comprises adiamine and otherwise R⁵ including R⁶ comprises a diamine,

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of the remaining ofpositions 1 to 5 are optionally a heteroatom selected from N forposition 1 and any double bond position and otherwise S, O or NH forpositions 2 to 5, provided that not more than one ring position is S orO, and further provided that only one N is present if R⁴ comprises an N,no N is present if R⁴ comprises a diamine and otherwise R⁵ comprises adiamine,

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of positions 1 to 5are optionally a heteroatom selected from N for position 1, the positionto which R⁶ is bound if such position does not comprise C, and anydouble bond position and otherwise S, O or NH for positions 2 to 5,provided that not more than one position is S or O, and further providedthat R⁵ including R⁶ comprises only one N if R⁴ comprises an N, no N ispresent if R⁴ comprises a diamine and otherwise R⁵ including R⁶comprises a diamine,

where one or more of positions 1 to 6 are a heteroatom selected from Nfor position 1 and S, O or NH for positions 2 to 6, provided that R⁵together with R⁶ comprises only one N if R⁴ comprises an N, no N ispresent if R⁴ comprises a diamine and otherwise R⁵ including R⁶comprises a diamine.

where none, one or two of positions 1 to 6 are a heteroatom selectedfrom N for position 1 and the position to which R⁶ is bound if suchposition does not comprise C, and otherwise S, O or NH, provided that R⁵including R⁶ comprises only one N if R⁴ comprises an N, no N is presentif R⁴ comprises a diamine and otherwise R⁵ including R⁶ comprises adiamine,

where at least one bond between adjacent ring atoms is a double bond,and one or more of positions 1 to 6 are a heteroatom selected from N forposition 1 and any double bond position and otherwise S, O or NH orN—(CH₂)_(y)—CH₃ for positions 2 to 6, provided that not more than twopositions are S or O, and further provided that R⁵ together with R⁶comprises only one N if R⁴ comprises an N, no N is present if R⁴comprises a diamine and otherwise R⁵ including R⁶ comprises a diamine,

where at least one bond between adjacent ring atoms is a double bond,and one or more of positions 1 to 6 are optionally a heteroatom selectedfrom N for position 1 and any double bond position and otherwise S, O orNH for positions 2 to 6, provided that not more than two positions are Sor O, and further provided that R⁵ including R⁶ comprises only one N ifR⁴ comprises an N, no N is present if R⁴ comprises a diamine andotherwise R⁵ including R⁶ comprises a diamine,

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of the remaining ofpositions 1 to 6 are optionally a heteroatom selected from N forposition 1 and any double bond position and otherwise S, O or NH forpositions 2 to 6, provided that not more than two positions are S or O,and further provided that only one N is present if R⁴ comprises an N, noN is present if R⁴ comprises a diamine and otherwise R⁵ comprises adiamine, or

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of positions 1 to 6are optionally a heteroatom selected from N for position 1, the positionto which R⁶ is bound if such position does not comprise C, and anydouble bond position and otherwise S, O or NH for positions 2 to 6,provided that not more than two positions are S or O, and furtherprovided that R⁵ including R⁶ comprises only one N if R⁴ comprises an N,no N is present if R⁴ comprises a diamine and otherwise R⁵ including R⁶comprises a diamine;

-   R⁶ is hydroxyl, (CH₂)_(y)-CH₃, (CH₂)_(y)-NH₂, NH₂, NH—(CH₂)_(y)-CH₃    or N(—(CH₂)_(y)-CH₃)₂;-   t is an index value from 0 to 6;-   y is in each instance independently an index value from 0 to 5;and-   z is an index value from 1 to 6;-   provided that, any NH or NH₂ in the foregoing may be substituted by    N-Prg or NH-Prg, respectively, where each Prg is independently an    amine protecting group.

In the foregoing depictions of ring structures containing a circlewithin the ring, it is to be understood that the ring structure mayinclude only one double bond, or may include more than one double bond,and in particular, the use of the circle does not imply that allpossible double bonds are present.

Where a Prg is present, each Prg may independently be acetyl,adamantyloxy, benzoyl, benzyl, benzyloxy, t-butoxycarbonyl,mesitylene-2-sulfonyl, 4-methoxy-2,3-6-trimethyl-benzenesulfonyl,2,2,4,6,7-pentamethyldihydrobenzofurane-5-sulfonyl,2,2,5,7,8-pentamethylchromane-6-sulfonyl, or tosyl.

In another aspect of the compound of structure I, W is

where R⁴ is

-   -   NH,    -   O, provided that R⁵ comprises a diamine,    -   CH₂, provided that R⁵ comprises a diamine,    -   N(—CH₂)_(z) where N(CH₂)_(z) together with R⁵ forms a ring,    -   N(—(CH₂)_(y)-CH₃),    -   NH—C(═O),    -   NH—C(═O)—NH, provided that R⁵ does not comprise an N,    -   C(═O), provided that R⁵ comprises a diamine,    -   C(═O)—NH,    -   C(═O)—O, provided that R⁵ comprises a diamine, or    -   O—C(═O), provided that R⁵ comprises a diamine;        R⁵is    -   NH₂, provided that R⁴ comprises one N,    -   hydroxyl, provided that R⁴ comprises a diamine,    -   CH₃, provided that R⁴ comprises a diamine,    -   NH—(CH₂)_(z), where NH—(CH₂)_(z) together with R⁴ forms a ring,    -   NH—(CH₂)_(y)-CH₃,    -   N(—(CH₂)_(y)-CH₃)₂,    -   NH—(CH₂)_(z)-NH₂,    -   NH—(CH₂)_(z)-NH—(CH₂)_(y)-CH₃,    -   NH—(CH₂)_(z)-N—((CH₂)_(y)-CH₃)₂,    -   N(—(CH2)_(y)-CH₃)—(CH₂)_(z)-NH(CH₂)_(y)-CH₃,    -   N(—(CH₂)_(y)-CH₃)—(CH₂))_(z)-N((CH₂)_(y)-CH₃)₂,    -   NH—C(═O)—(CH₂)_(y)-NH₂,    -   O—(CH₂)_(y)-CH₃, provided that R⁴ comprises a diamine,    -   SO₂—NH₂,    -   SO₂—NH—(CH₂)_(y)-CH₃,    -   SO₂—N(—(CH₂)_(y)-CH₃)₂,    -   SO₂—(CH₂)_(y)-CH₃, provided that R⁴ comprises a diamine,

where none, one or more of positions 1 to 5 are a heteroatom selectedfrom N for position 1 and S, O or NH for positions 2 to 5, provided thatonly one N is present if R⁴ comprises an N, no N is present if R⁴comprises a diamine and otherwise R⁵ comprises a diamine,

where none, one or two of positions 1 to 5 are a heteroatom selectedfrom N for position 1 and for the position to which R⁶ is bound if suchposition does not comprise C, and otherwise S, O or NH, provided that R⁵including R⁵ comprises only one N if R⁴ comprises an N, no N is presentif R⁴ comprises a diamine and otherwise R⁵ including R⁶ comprises adiamine,

where at least one bond between adjacent ring atoms is a double bond,and none or one or more of positions 1 to 5 are a heteroatom selectedfrom N for position 1 and any double bond position and otherwise S, O orNH for positions 2 to 5, provided that not more than one position is Sor O, and further provided that only one N is present if R⁴ comprises anN, no N is present if R⁴ comprises a diamine and otherwise R⁵ comprisesa diamine,

where at least one bond between adjacent ring atoms is a double bond,and one or more of positions 1 to 5 are optionally a heteroatom selectedfrom N for position 1, the position to which R⁶ is bound if suchposition does not comprise C, and any double bond position and otherwiseS, O or NH for positions 2 to 5, provided that not more than oneposition is S or O, and further provided that R⁵ including R⁶ comprisesonly one N if R⁴ comprises an N, no N is present if R⁴ comprises adiamine and otherwise R⁵ including R⁶ comprises a diamine,

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of the remaining ofpositions 1 to 5 are optionally a heteroatom selected from N forposition 1 and any double bond position and otherwise S, O or NH forpositions 2 to 5, provided that not more than one ring position is S orO, and further provided that only one N is present if R⁴ comprises an N,no N is present if R⁴ comprises a diamine and otherwise R⁵ comprises adiamine,

where at least one bond between adjacent ring atoms is a double bond,the hydroxyl is bound to a ring carbon, and one or more of positions 1to 5 are optionally a heteroatom selected from N for position 1, theposition to which R⁶ is bound if such position does not comprise C, andany double bond position and otherwise S, O or NH for positions 2 to 5,provided that not more than one position is S or O, and further providedthat R⁵ including R⁶ comprises only one N if R⁴ comprises an N, no N ispresent if R⁴ comprises a diamine and otherwise R⁵ including R⁶comprises a diamine,

where one or more of positions 1 to 6 are a heteroatom selected from Nfor position 1 and S, O or NH for positions 2 to 6, provided that R⁵together with R⁶ comprises only one N if R⁴ comprises an N, no N ispresent if R⁴ comprises a diamine and otherwise R⁵ including R⁶comprises a diamine,

where none, one or two of positions 1 to 6 are a heteroatom selectedfrom N for position 1 and the position to which R⁶ is bound if suchposition does not comprise C, and otherwise S, O or NH, provided that R³including R⁶ comprises only one N if R⁴ comprises an N, no N is presentif R⁴ comprises a diamine and otherwise R⁵ including R⁶ comprises adiamine,

where at least one bond between adjacent ring atoms is a double bond,and one or more of positions 1 to 6 are a heteroatom selected from N forposition 1 and any double bond position and otherwise S, O or NH orN—(CH₂)_(y)-CH₃ for positions 2 to 6, provided that not more than twopositions are S or O, and further provided that R⁵ together with R⁶comprises only one N if R⁴ comprises an N, no N is present if R⁴comprises a diamine and otherwise R⁵ including R⁶ comprises a diamine,

where at least one bond between adjacent ring atoms is a double bond,and one or more of positions 1 to 6 are optionally a heteroatom selectedfrom N for position 1 and any double bond position and otherwise S, O orNH for positions 2 to 6, provided that not more than two positions are Sor O, and further provided that R⁵ including R⁶ comprises only one N ifR⁴ comprises an N, no N is present if R⁴ comprises a diamine andotherwise R⁵ including R⁶ comprises a diamine,

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of the remaining ofpositions 1 to 6 are optionally a heteroatom selected from N forposition 1 and any double bond position and otherwise S, O or NH forpositions 2 to 6, provided that not more than two positions are S or O,and further provided that only one N is present if R⁴ comprises an N, noN is present if R⁴ comprises a diamine and otherwise R⁵ comprises adiamine, or

where at least one bond between adjacent ring atoms is a double bond,the oxo is bound to a ring carbon, and one or more of positions 1 to 6are optionally a heteroatom selected from N for position 1, the positionto which R⁶ is bound if such position does not comprise C, and anydouble bond position and otherwise S, O or NH for positions 2 to 6,provided that not more than two positions are S or O, and furtherprovided that R⁵ including R⁶ comprises only one N if R⁴ comprises an N,no N is present if R⁴ comprises a diamine and otherwise R⁵ including R⁶comprises a diamine;

-   R⁶ is hydroxyl, (CH₂)_(y)-CH₃, (CH₂)_(y)-NH₂, NH₂, NH—(CH₂)_(y)-CH₃    or N(—(CH₂)_(y)-CH₃)₂;-   R⁷ is a C₄ to C₁₀ aliphatic comprising an optionally substituted    cycloalkane or aryl ring;-   y is in each instance independently an index value from 0 to 5;and-   z is an index value from 1 to 6;    wherein any NH or NH₂ in the foregoing may be substituted by N-Prg    or NH-Prg, respectively, where each Prg is independently an amine    protecting group.

In the foregoing depictions of ring structures containing a circlewithin the ring, it is to be understood that the ring structure mayinclude only one double bond, or may include more than one double bond,and in particular, the use of the circle does not imply that allpossible double bonds are present.

Here too if Prg is present each Prg may independently be acetyl,adamantyloxy, benzoyl, benzyl, benzyloxycarbonyl, t-butoxycarbonyl,mesitylene-2-sulfonyl, 4-methoxy-2,3-6-trimethyl-benzenesulfonyl,2,2,4,6,7-pentamethyldihydrobenzofurane-5-sulfonyl,2,2,5,7,8-pentamethylchromane-6-sulfonyl, 9-fluorenylmethoxycarbonyl ortosyl.

In one aspect of the compound of structure I, one of R^(2a) and R^(2b)is

and the remaining of R^(2a) and R^(2b) and both R^(1a) and R^(1b) arehydrogen.

The invention further provides a compound having the formula ofstructure II

or an enantiomer, stereoisomer or diastereoisomer thereof, or apharmaceutically acceptable salt thereof,wherein

-   one or two of R^(1a), R^(1b), R^(2a), and R^(2b) are independently a    C₁ to C₆ aliphatic linear or branched chain and the remaining of    R^(1a), R^(1b), R^(2a), and R^(2b) are hydrogen, provided that at    least one of R^(1a), and R^(1b) and at least one of R^(2a) and    R^(2b) are hydrogen;-   or one of R^(1a), R^(1b), R^(2a), and R^(2b) are

and the remaining of R^(1a), R^(1b), R^(2a), and R^(2b) are hydrogen;

-   or R^(1a) and R^(1b) together form ═O and one of R^(2a) and R^(2b)    is a C₁ to C₆ aliphatic linear or branched chain,

and the remaining of R^(2a) and R^(2b) is hydrogen;

-   R^(4a) is NH, N(—(CH₂)_(y)-CH₃), NH—C(═O), or C(═O)—NH;-   R^(5a) is NH₂, NH—(CH₂)_(y)-CH₃, or N(—(CH₂)_(y)-CH₃)₂;-   y is in each instance independently an index value from 0 to 5;-   the groups —C(R⁸)CH(R⁹)(CH₂)_(y)-Q and —C(R⁸)CH(R⁹)(CH₂)_(y)-J are    the same and, in those groups    -   R⁸ is H or ═O;    -   R⁹ is hydrogen or N(R^(10a))R^(10b);    -   R^(10a) and R^(10b) are independently hydrogen, acetyl, methyl,        ethyl, propyl, isopropyl, butyl, pentyl, hexyl, isobutyl,        benzyl, benzoyl, hexanoyl, propionyl, butanoyl, pentanoyl,        heptanoyl, cyclopropyl, cyclopropylmethyl, cyclobutyl,        cyclobutylmethyl, cyclohexyl or cyclohexylmethyl;    -   Q and J are the same and represent an aromatic carbocyclic ring        selected from the group consisting of phenyl, substituted        phenyl, naphthyl and substituted naphthyl; and    -   z is an index value from 1 to 6;        wherein the carbon atoms marked with an asterisk can have any        stereochemical configuration.

In another aspect of the invention there is provided a pharmaceuticalcomposition comprising a compound of structure I or structure II and apharmaceutically acceptable carrier. The use of such pharmaceuticalcomposition is further provided, such as use for affecting melanocortinreceptor function in a human or non-human mammal by administering thepharmaceutical composition. There is further provided use of thepharmaceutical composition for making a medicament for treating acondition responsive to changes in melanocortin receptor function in ahuman or non-human mammal. In such use, the condition may be selectedfrom the group consisting of male sexual dysfunction, female sexualdysfunction, an eating disorder, above optimal body weight, obesity,below-optimal body weight and cachexia.

The present invention further provides compounds that are agonists of amelanocortin receptor, including one or more of MC1-R, MC3-R, MC4-R, orMC5-R. The compounds alternatively are antagonists of a melanocortinreceptor, including one or more of MC1-R, MC3-R, MC4-R, or MC5-R. Thecompounds alternatively are inverse agonists of a melanocortin receptor,including one or more of MC1-R, MC3-R, MC4-R, or MC5-R. The compoundsalternatively are antagonists of an inverse agonist of a melanocortinreceptor, including one or more of MC1-R, MC3-R, MC4-R, or MC5-R.

The invention further includes methods for altering a disorder orcondition associated with the activity of a melanocortin receptor,comprising administering to a patient a pharmaceutically effectiveamount a compound of this invention. In one embodiment the disorder orcondition is an eating disorder such as cachexia. In another embodimentthe disorder or condition is obesity and associated impairment of energyhomeostasis. In yet another embodiment the disorder or condition issexual dysfunction such as erectile dysfunction or female sexualdysfunction.

One object of the present invention is to provide conformationallyconstrained and optically pure isomers of tetra-substituted piperazine,wherein the pendant group substituents are amino acid moieties, aminoacid side chain moieties or derivatives thereof, such that the resultingring compound biologically mimics a relevant reverse turn peptidestructure.

Another object of the present invention is to provide methods for thesynthesis of optically pure tetra-substituted piperazine compounds.

Another object of the present invention is to provide piperazine corecompounds wherein pendant groups are provided, which pendant groups areor include amino acid side chain moieties.

Another object of the present invention is to provide atetra-substituted piperazine compound wherein such compound is specificfor one or more melanocortin receptors.

Another object of the present invention is to provide a method forsynthesis of tetra-substituted piperazine compounds of the invention.

In this invention it is disclosed that piperazine rings may be employedwith four descriptors, wherein each descriptor is a pendant groupattached to a given ring atom, and where one descriptor includes adiamine group. At least two, and optionally all three, of the remainingpendant groups comprise a ring structure, wherein the ring in each ofthe descriptors or pendant groups is carbocyclic, and where at least twoof such rings are aromatic. By employing four descriptors, the inventorshave further found that the chirality of the ring, and stereo structuregenerally, is fixed in a desired structure, thereby more closelymimicking the desired pharmacophores, and with the descriptorspositioned in the most relevant chemical space.

The invention further also relates to enantiomerically puretetra-substituted piperazines, preferably made by the synthetic schemesdisclosed herein or variants thereof. A classical piperazine ring is aconformationally dynamic six-membered ring structure. It can exist in avariety of conformational states, commonly referred to as chair, boat,twisted chair or twisted boat conformations. Because of this dynamism instructural states, the location of descriptors on the ring plays animportant role in stabilizing the ring in a single conformational state;if the appropriate conformational state is selected, this is conduciveto making a molecule more selective for its receptor. For example, a 1,3axial placement of two bulky descriptors generally causes unfavorablesteric interactions between these two groups, and thus make a chairconformation energetically less stable. Consequently, the chairconformation is less preferred, resulting in a twisted chair or boatconformation. The twisted chair or boat conformation results in aspecific stereochemical alignment of the descriptors, which isspecifically relevant to interaction with the desired receptor. Thus, aconformation resulting from 1,3 axial placement of two descriptors mayresult in a structure more selective for a given receptor sub-type.

In yet another embodiment, the invention describes tetra-substitutedpiperazine compounds in which one substituted group includes a diaminewhich are specific for G-protein coupled receptor systems, such systemsincluding, but not limited to, melanotropin or melanocortin receptors(MC1-R, MC3-R, MC4-R and MC5-R).

DEFINITIONS

Before proceeding further with the description of the invention, certainterms are defined as set forth herein.

The “amino acid” and “amino acids” used in this invention, and the termsas used in the specification and claims, include the known naturallyoccurring protein amino acids, which are referred to by both theircommon three letter abbreviation and single letter abbreviations. Seegenerally Synthetic Peptides: A User's Guide, G A Grant, editor, W.H.Freeman & Co., New York, 1992, the teachings of which are incorporatedherein by reference, including the text and table set forth at pages 11through 24. As set forth above, the term “amino acid” also includesstereoisomers and modifications of naturally occurring protein aminoacids, non-protein amino acids, post-translationally modified aminoacids, enzymatically synthesized amino acids, derivatized amino acids,constructs or structures designed to mimic amino acids, and the like.Modified and unusual amino acids are described generally in SyntheticPeptides: A User's Guide, cited above; Hruby V J, Al-obeidi F andKazmierski W: Biochem J 268:249-262, 1990;and Toniolo C: Int J PeptideProtein Res 35:287-300, 1990;the teachings of all of which areincorporated herein by reference.

The term “amino acid side chain moiety” used in this invention includesany side chain of any amino acid, as the term “amino acid” is definedherein, including any derivative of an amino acid side chain moiety, asthe term “derivative” is defined herein. This thus includes the sidechain moiety present in naturally occurring amino acids. It furtherincludes side chain moieties in modified naturally occurring aminoacids, such as glycosylated amino acids. It further includes side chainmoieties in stereoisomers and modifications of naturally occurringprotein amino acids, non-protein amino acids, post-translationallymodified amino acids, enzymatically synthesized amino acids, derivatizedamino acids, constructs or structures designed to mimic amino acids, andthe like. For example, the side chain moiety of any amino acid disclosedherein is included within the definition of an amino acid side chainmoiety.

The “derivative” of an amino acid side chain moiety includes anymodification to or variation in any amino acid side chain moieties,including a modification of naturally occurring amino acid side chainmoieties. By way of example, derivatives of amino acid side chainmoieties include straight chain or branched, cyclic or noncyclic,substituted or unsubstituted, and saturated or unsaturated alkyl, arylor aralkyl moieties.

In the listing of compounds according to the present invention,conventional amino acid residues have their conventional meaning asgiven in Chapter 2400 of the Manual of Patent Examining Procedure,8^(th) Ed. Thus, “Nle” is norleucine; “Asp” is aspartic acid; “His” ishistidine; “D-Phe” is D-phenylalanine; “Arg” is arginine; “Trp” istryptophan; “Lys” is lysine; “Gly” is glycine; “Pro” is proline; “Tyr”is tyrosine, “Ser” is serine and so on.

In the specification and the claims, the term “homolog” includes,without limitation, (a) a D-amino acid residue or side chain substitutedfor an L-amino acid residue side chain, (b) a post-translationallymodified residue or side chain substituted for the residue or sidechain, (c) a non-peptide or other modified amino acid residue or sidechain based on another such residue or side chain, such asphenylglycine, homophenylalanine, ring-substituted halogenated, andalkylated or arylated phenylalanines for a phenylalanine residue,diamino propionic acid, diamino butyric acid, ornithine, lysine andhomoarginine for an arginine residue, and the like, and (d) any aminoacid residue or side chain, coded or otherwise, or a construct orstructure that mimics an amino acid residue or side chain, and which hasat least a similarly charged side chain (neutral, positive or negative),preferably a similar hydrophobicity or hydrophilicity, and preferably asimilar side chain in terms of being a saturated aliphatic side chain, afunctionalized aliphatic side chain, an aromatic side chain or aheteroaromatic side chain.

The term “alkene” includes unsaturated hydrocarbons that contain one ormore double carbon-carbon bonds. Examples of such alkene groups includeethylene, propene, and the like.

The term “alkenyl” includes a linear monovalent hydrocarbon radical oftwo to six carbon atoms or a branched monovalent hydrocarbon radical ofthree to six carbon atoms containing at least one double bond; examplesthereof include ethenyl, 2-propenyl, and the like.

The “alkyl” groups specified herein include those alkyl radicals ineither a straight or branched configuration. Examples of such alkylradicals include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl,tertiary butyl, pentyl, isopentyl, hexyl, isohexyl, and the like.

The term “alkynyl” includes a linear monovalent hydrocarbon radical oftwo to six carbon atoms or a branched monovalent hydrocarbon radical ofthree to six carbon atoms containing at least one triple bond; examplesthereof include ethynyl, propynyl, butynyl, and the like.

The term “aryl” includes a monocyclic or bicyclic aromatic hydrocarbonradical of 6 to 12 ring atoms, and optionally substituted independentlywith one or more substituents selected from alkyl, haloalkyl,cycloalkyl, alkoxy, alkythio, halo, nitro, acyl, cyano, amino,monosubstituted amino, disubstituted amino, hydroxy, carboxy, oralkoxy-carbonyl. Examples of an aryl group include phenyl, biphenyl,naphthyl, 1-naphthyl, and 2-naphthyl, derivatives thereof, and the like.

The term “aralkyl” includes a radical —R^(a)R^(b) where R^(a) is analkylene (a bivalent alkyl) group and R^(b) is an aryl group as definedabove. Examples of aralkyl groups include benzyl, phenylethyl,3-(3-chlorophenyl)-2-methylpentyl, and the like.

The term “aliphatic” includes compounds with hydrocarbon chains, such asfor example alkanes, alkenes, alkynes, and derivatives thereof.

The term “acyl” includes a group RCO—, where R is an organic group. Anexample is the acetyl group CH₃CO—.

A group or aliphatic moiety is “acylated” when an alkyl or substitutedalkyl group as defined above is bonded through one or more carbonyl[—(C═O)—] groups.

An “omega amino derivative” includes an aliphatic moiety with a terminalamino group. Examples of omega amino derivatives include aminoheptanoyland the amino acid side chain moieties of ornithine and lysine.

The term “heteroaryl” includes mono- and bicyclic aromatic ringscontaining from 1 to 4 heteroatoms selected from nitrogen, oxygen andsulfur. 5- or 6-membered heteroaryl are monocyclic heteroaromatic rings;examples thereof include thiazole, oxazole, thiophene, furan, pyrrole,imidazole, isoxazole, pyrazole, triazole, thiadiazole, tetrazole,oxadiazole, pyridine, pyridazine, pyrimidine, pyrazine, and the like.Bicyclic heteroaromatic rings include, but are not limited to,benzothiadiazole, indole, benzothiophene, benzofuran, benzimidazole,benzisoxazole, benzothiazole, quinoline, benzotriazole, benzoxazole,isoquinoline, purine, furopyridine and thienopyridine.

An “amide” includes compounds that have a trivalent nitrogen attached toa carbonyl group (—CO—NH₂), such as methylamide, ethylamide,propylamide, and the like.

An “imide” includes compounds containing an imido group (—CO—NH—CO—).

An “amine” includes compounds that contain an amino group (—NH₂).

A “nitrile” includes compounds that are carboxylic acid derivatives andcontain a (—CN) group bound to an organic group.

An amino acid side chain moiety is “hydrogen bonding” when the sidechain includes hydrogen bond donors and/or hydrogen bond acceptors.

An “amine capping group” includes any terminal group attached through aterminal amine, including but not limited to any omega amino derivative,acyl group or terminal aryl or aralkyl, including groups such as a C₁ toC₆ linear or branched chain such as methyl, dimethyl, ethyl, propyl,isopropyl, butyl, isobutyl, pentyl, or hexyl, groups such as allyl,cyclopropane methyl, hexanoyl, heptanoyl, acetyl, propionoyl, butanoyl,phenylacetyl, cyclohexylacetyl, naphthylacetyl, cinnamoyl, phenyl,benzyl, benzoyl, 12-Ado, 7′-amino heptanoyl, 6-Ahx, Amc or 8-Aoc, or amolecule such as polyethylene glycol with a formula molecular weight ofbetween 100 and 50,000.

The term “composition”, as in pharmaceutical composition, is intended toencompass a product comprising the active ingredient(s), and the inertingredient(s) that make up the carrier, as well as any product whichresults, directly or indirectly, from combination, complexation oraggregation of any two or more of the ingredients, or from dissociationof one or more of the ingredients, or from other types of reactions orinteractions of one or more of the ingredients. Accordingly, thepharmaceutical compositions of the present invention encompass anycomposition made by admixing a compound of the present invention and oneor more pharmaceutically acceptable carriers and/or other excipients,and optionally one or more other pharmaceutically active ingredients andagents.

A variety of chemicals and compounds are employed in this invention, andthe following abbreviations have the meanings given:

Boc tertiary butyloxycarbonyl Cbz benzyloxycarbonyl DCM dichloromethaneDIAD diisopropyl azodicarboxylate DMF N,N-dimethylformamide DMSOdimethyl sulfoxide EDC N-(3-dimethylaminopropyl)-N′-ethylcarbodiimidehydrochloride EtOAc ethyl acetate Fmoc 9-fluorenylmethoxycarbonyl HEPES4-(2-hydroxyethyl)1-piperazineethanesulfonic acid HOAt1-hydroxy-7-azabenzotriazole IBCF isobutyl chloroformate LAH lithiumaluminum hydride NMM N-methylmorpholine Pd/C palladium on carbon TBTU2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborateTEA triethylamine THF tetrahydrofuran TPP triphenylphosphine

A “tetra-substituted piperazine”, as used herein, is a piperazinecompound or derivative thereof wherein a group other than solely H, andpreferably including an amino acid residue or an amino acid side chainmoiety, is attached to each ring N member, and further wherein groupsother than solely H, O, S or a halogen, preferably including an aminoacid side chain moiety, are attached to two ring C members.

“Sexual dysfunction” means any condition that inhibits or impairs normalsexual function, including coitus. The term is not limited tophysiological conditions, and includes psychogenic conditions orperceived impairment without a formal diagnosis of pathology ordisorder. Sexual dysfunction includes erectile dysfunction in a malemammal and female sexual dysfunction in a female mammal.

“Erectile dysfunction” is a disorder involving the failure of a malemammal to achieve functional erection, ejaculation, or both. Erectiledysfunction is accordingly synonymous with impotence, and may includethe inability to attain or sustain an erection of sufficient rigidityfor coitus. Symptoms of erectile dysfunction include an inability toachieve or maintain an erection, ejaculatory failure, prematureejaculation, or inability to achieve an orgasm, which symptoms may occurseparately or in any combination. An increase in erectile dysfunction isoften associated with age or may be caused by a physical disease or as aside-effect of drug treatment.

“Female sexual dysfunction” is a disorder including sexual arousaldisorder. The term “sexual arousal disorder” includes a persistent orrecurrent failure to attain or maintain the lubrication-swellingresponse of sexual excitement until completion of sexual activity.Sexual dysfunction in females may also include inhibited orgasm anddyspareunia, which is painful or difficult coitus. Female sexualdysfunction includes, but is not limited to, a number of categories ofdiseases, conditions and disorders including hypoactive sexual desiredisorder, sexual anhedonia, sexual arousal disorder, dyspareunia andvaginismus. Hypoactive sexual desire disorder includes a disorder inwhich sexual fantasies and desire for sexual activity are persistentlyor recurrently diminished or absent, causing marked distress orinterpersonal difficulties. Hypoactive sexual desire disorder can becaused by boredom or unhappiness in a long-standing relationship,depression, stress, dependence on alcohol or psychoactive drugs, sideeffects from prescription drugs, or hormonal deficiencies. Sexualanhedonia includes decreased or absent pleasure in sexual activity.Sexual anhedonia can be caused by depression, drugs, or interpersonalfactors. Sexual arousal disorder can be caused by reduced estrogen,illness, or treatment with diuretics, antihistamines, antidepressants orantihypertensive agents. Dyspareunia and vaginismus are sexual paindisorders characterized by pain resulting from penetration and may becaused, for example, by medications which reduce lubrication,endometriosis, pelvic inflammatory disease, inflammatory bowel diseaseor urinary tract problems.

By a melanocortin receptor “agonist” is meant an endogenous or drugsubstance or compound, including a compound of this invention, which caninteract with a melanocortin receptor and initiate a pharmacologicalresponse characteristic of the melanocortin receptor. By a melanocortinreceptor “antagonist” is meant a drug or a compound, including acompound of this invention, which opposes the melanocortinreceptor-associated responses normally induced by a melanocortinreceptor agonist agent.

By “binding affinity” is meant the ability of a compound or drug to bindto its biological target.

The chemical naming protocol and structure diagrams used herein employand rely on the chemical naming features as utilized by the ChemDrawprogram (available from Cambridgesoft Corp.) or ISIS Draw (MDLInformation Systems, Inc.). In particular, the compound names werederived from the structures using the Autonom program as utilized byChemDraw Ultra or ISIS Draw.

Clinical Applications

The compounds disclosed herein can be used for both medical applicationsand animal husbandry or veterinary applications. Typically, the productis used in humans, but may also be used in other mammals. The term“patient” is intended to denote a mammalian individual, and is so usedthroughout the specification and in the claims. The primary applicationsof this invention involve human patients, but this invention may beapplied to laboratory, farm, zoo, wildlife, pet, sport or other animals.

Melanocortin receptor-specific compounds of this invention that areMC1-R specific can be used as chemoprevention agents againstsun-induced, such as by UV radiation, neoplastic activity in human skin.MC1-R agonist compounds of this invention may be employed to stimulateepidermal melanocytes to produce melanin as well as to convertpheomelanin to eumelanin. Eumelanin, which is dark brown or blackpigmentation, is considered more photo-protective than pheomelanin,which is yellow or red pigmentation. The process of melanogenesis isbelieved to involve stimulation of MC1-R in epidermal melanocytes,thereby mediating the stimulation of tyrosinase enzymes within thesepigment cells, inducing the conversion of tyrosine to dopa and thenthrough dopaquinone to eumelanin. Sun tanning due to direct sun exposureis proposed to result from the same pathway by local production ofmelanotropic peptide from a POMC gene in the epidermis. Thus,stimulation of eumelanin production and conversion of pheomelanin toeumelanin may be a desirable chemoprevention modality in blocking sun-or UV-induced neoplastic activity in skin. A potent, high-affinity andhighly selective MC1-R agonist compound of this invention canaccordingly be used as a therapeutic chemoprevention agent for combatingharmful sun or UV exposure that induces neoplastic activity in skinmelanocytes.

In another embodiment, compounds of this invention, including but notlimited to compounds that are MC4-R agonists, partial agonists orfunctionally inactive may be used as a therapeutic agent to modifyenergy metabolism and feeding behavior, including treatment ofpathologic obesity and related conditions. In addition to use intreatment of patients clinically diagnosed as obese, compounds of thisinvention may be employed with persons who are above optimal bodyweight, as an aid in weight loss. Compounds of this invention, includingbut not limited to MC4-R antagonists, may be used as a therapeutic agentin eating disorders, such as treatment of anorexia and cachexia, whichis malnutrition and wasting due to illness. In addition to use intreatment of patients diagnosed with anorexia or cachexia, compounds ofthis invention may be employed with persons who have below optimal bodyweight, and in particular with patients desiring to gain additionalmuscle mass.

In yet another embodiment, compounds of this invention can be used astherapeutic agents for treatment of sexual dysfunction, includingtreatment of both male erectile dysfunction and female sexualdysfunction.

In yet another embodiment, compounds of this invention may be used astherapeutic agents for treatment of inflammation, including specificallyMC1-R, MC3-R and MC5-R agonists.

In yet another embodiment of the invention, compounds of this inventionthat are MC5-R specific can be used as agents to decrease sebumproduction, and thus may be efficacious in the treatment of acne andrelated diseases. The compounds for this application may be convenientlyformulated for local administration, as through a gel, lotion, cream orother topical formulation.

In yet another embodiment, compounds of this invention may be employedin the treatment of drug or alcohol dependence, depression, anxiety andrelated conditions and indications.

Formulations and Administration.

The compounds may be formulated by any means, such as those known in theart, including but not limited to tablets, capsules, caplets,suspensions, powders, lyophilized forms and aerosols/aerosolizableformulations and may be mixed and formulated with buffers, binders,stabilizers, anti-oxidants and other agents known in the art. Thecompounds may be administered by any systemic or partially systemicmeans such as those known in the art, including but not limited tointravenous injection, subcutaneous injection, administration throughmucous membranes, oral administration, dermal administration, skinpatches, aerosols and the like.

The invention further provides a pharmaceutical composition thatincludes a compound of this invention and a pharmaceutically acceptablecarrier. The compound of this invention may thus be formulated orcompounded into pharmaceutical compositions that include at least onecompound of this invention together with one or more pharmaceuticallyacceptable carriers, including excipients, such as diluents, carriersand the like, and additives, such as stabilizing agents, preservatives,solubilizing agents, buffers and the like, as may be desired.

Formulation excipients may include polyvinylpyrrolidone, gelatin,hydroxy cellulose, acacia, polyethylene glycol, mannitol, sodiumchloride or sodium citrate. For injection or other liquid administrationformulations, water containing at least one or more bufferingconstituents is suitable, and stabilizing agents, preservatives andsolubilizing agents may also be employed. For solid administrationformulations, any of a variety of thickening, filler, bulking andcarrier additives may be employed, such as starches, sugars, fatty acidsand the like. For topical administration formulations, any of a varietyof creams, ointments, gels, lotions and the like may be employed. Formost pharmaceutical formulations, non-active ingredients will constitutethe greater part, by weight or volume, of the preparation. Forpharmaceutical formulations, it is also contemplated that any of avariety of measured-release, slow-release or time-release formulationsand additives may be employed, such that the dosage may be formulated soas to effect delivery of a compound of this invention over a period oftime.

The compounds of this invention may be in the form of anypharmaceutically acceptable salt. Acid addition salts of the compoundsof this invention are prepared in a suitable solvent from the compoundand an excess of an acid, such as hydrochloric, hydrobromic, sulfuric,phosphoric, acetic, trifluoroacetic, maleic, succinic ormethanesulfonic. The acetate salt form is especially useful. Where thecompounds of this invention include an acidic moiety, suitablepharmaceutically acceptable salts may include alkali metal salts, suchas sodium or potassium salts, or alkaline earth metal salts, such ascalcium or magnesium salts.

The compounds and pharmaceutical compositions of this invention may beadministered by injection, which injection may be intravenous,subcutaneous, intramuscular, intraperitoneal or by any other means knownin the art. In general, any route of administration by which thecompounds of this invention are introduced across an epidermal layer ofcells may be employed. Administration means may include administrationthrough mucous membranes, buccal administration, oral administration,dermal administration, inhalation administration, nasal administrationand the like. The dosage for treatment is administration, by any of theforegoing means or any other means, of an amount sufficient to bringabout the desired therapeutic effect.

One advantageous route of administration is nasal administration, suchas by means of a liquid spray, gel or powder. In one route ofadministration, an aqueous solution is employed, preferably administeredby means of a metered delivery device. By “nasal administration” ismeant any form of intranasal administration of any of the compounds andpharmaceutical compositions of this invention. Thus in one embodiment,compounds and pharmaceutical compositions of this invention include anaqueous solution, such as a solution including saline, citrate or othercommon excipients or preservatives, formulated for intranasaladministration. In another embodiment, compounds and pharmaceuticalcompositions of this invention include a dry or powder formulation,formulated for intranasal administration. A preparation for nasaladministration can take a variety of forms, such as for administrationin nasal drops, nasal spray, gel, ointment, cream, powder or suspension.A variety of dispensers and delivery vehicles are known in the art,including single-dose ampoules, metered dose devices, atomizers,nebulizers, pumps, nasal pads, nasal sponges, nasal capsules, and thelike.

The pharmaceutical composition may be in a solid, semi-solid, or liquidform. For a solid form, the compound and other components may be mixedtogether by blending, tumble mixing, freeze-drying, solvent evaporation,co-grinding, spray-drying, and/or other techniques known in the art. Asemi-solid pharmaceutical composition suitable for intranasaladministration may take the form of an aqueous or oil-based gel orointment. For example, the compound and other components can be mixedwith microspheres of starch, gelatin, collagen, dextran, polylactide,polyglycolide or other similar materials that form hydrophilic gels. Inone embodiment, the microspheres can be internally loaded or coated withcompound, which upon administration forms a gel that adheres to thenasal mucosa. In another embodiment, the formulation is liquid, it beingunderstood that this includes, for example, an aqueous solution, anaqueous suspension, an oil solution, an oil suspension, or an emulsion,depending on the physicochemical properties of the compound and othercomponents.

For liquid formulations, excipients necessary or desirable forformulation, stability, and/or bioavailability may be included in thepharmaceutical composition. Exemplary excipients include sugars (such asglucose, sorbitol, mannitol, or sucrose), uptake enhancers (such aschitosan), thickening agents and stability enhancers (such ascelluloses, polyvinyl pyrrolidone, starch, and the like), buffers,preservatives, and/or acids and bases to adjust the pH. In oneembodiment, an absorption promoting component is included in thepharmaceutical composition. Exemplary absorption promoting componentsinclude surfactant acids, such as cholic acid, glycocholic acid,taurocholic acid, and other cholic acid derivatives, chitosan andcyclodextrins.

The pharmaceutical composition may further include optional componentssuch as humectants, preservatives and the like. A humectant ormoisturizing agent can be employed to decrease water loss from thepharmaceutical composition and optionally moisturize nasal mucosa.Exemplary humectants include hygroscopic materials such as glycerine,propylene glycol, polyethylene glycol, polysaccharides and the like.Preservatives may be employed, to prevent or limit bacteria and othermicrobial growth. One such preservative that may be employed isbenzalkonium chloride, such as 0.05% benzalkonium chloride. Otherpreservatives include, for example, benzyl alcohol, methylparaben,propylparaben, butylparaben, chlorobutanol, phenethyl alcohol, phenylmercuric acetate and the like.

The pharmaceutical composition may also include rheology modifyingagents, such as for varying the viscosity of the pharmaceuticalcomposition. Exemplary rheology modify agents include polymers andsimilar materials, such as sodium carboxymethyl cellulose, algin,carageenans, carbomers, galactomannans, hydroxypropyl methylcellulose,hydroxypropyl cellulose, polyethylene glycols, polyvinyl alcohol,polyvinylpyrrolidone, sodium carboxymethyl chitin, sodium carboxymethyldextran, sodium carboxymethyl starch, xanthan gum and combinations ofthe foregoing. Such agents may also act as bioadhesives, to extend theresidence time of a compound of the invention within the nasal mucosa.

Depending on the formulation and route of administration, an aqueoussolution of compounds or pharmaceutical compositions of this inventionmay be appropriately buffered by means of saline, acetate, phosphate,citrate, acetate or other buffering agents, which are at anyphysiologically acceptable pH, generally from about pH 4 to about pH 8.A combination of buffering agents may also be employed, such asphosphate buffered saline, a saline and acetate buffer, and the like. Inthe case of saline, a 0.9% saline solution may be employed. In the caseof acetate, phosphate, citrate, acetate and the like, a 50 mM solutionmay be employed.

In another route of administration, compounds and pharmaceuticalcompositions of this invention are administered directly into the lung.Intrapulmonary administration may be performed by means of a metereddose inhaler, a device allowing self-administration of a metered bolusof a compound and pharmaceutical composition of this invention whenactuated by a patient during inspiration. Both dry powder inhalation andnebulized aerosols may be employed. Thus, it is possible andcontemplated that compounds and pharmaceutical compositions of thisinvention may be in a dried and particulate form. In one embodiment, theparticles are between about 0.5 and 6.0 μm, such that the particles havesufficient mass to settle on the lung surface and not be exhaled, butare small enough that they are not deposited on surfaces of the airpassages prior to reaching the lung. Any of a variety of differenttechniques may be used to make dry powder microparticles, including butnot limited to micro-milling, spray drying and a quick freeze aerosolfollowed by lyophilization. With micro-particles, the constructs may bedeposited to the deep lung, thereby providing quick and efficientabsorption into the bloodstream. Further, with such an approach,penetration enhancers are not required, as is sometimes necessary withtransdermal, nasal or oral mucosal delivery routes. Any of a variety ofinhalers may be employed, including propellant-based aerosols,nebulizers, single dose dry powder inhalers and multidose dry powderinhalers. Common devices in current use include metered dose inhalers,which are used to deliver medications for the treatment of asthma,chronic obstructive pulmonary disease and the like. Preferred devicesinclude dry powder inhalers, designed to form a cloud or aerosol of finepowder with a particle size that is always less than about 6.0 μm.

Microparticle size, including mean size distribution, may be controlledby means of the method of making. For micro-milling, the size of themilling head, speed of the rotor, time of processing and the likecontrol the microparticle size. For spray drying, the nozzle size, flowrate, dryer heat and the like control the microparticle size. For makingby means of quick freeze aerosol followed by lyophilization, the nozzlesize, flow rate, concentration of aerosoled solution and the likecontrol the microparticle size. These parameters and others may beemployed to control the microparticle size.

The compounds and pharmaceutical compositions of this invention may beformulated for and administered by means of an injection, such as a deepintramuscular injection, such as in the gluteal or deltoid muscle, of atime release injectable formulation. In one embodiment, a compound orpharmaceutical composition of this invention is formulated with a PEG,such as poly(ethylene glycol) 3350, and optionally one or moreadditional excipients and preservatives, including but not limited toexcipients such as salts, polysorbate 80, sodium hydroxide orhydrochloric acid to adjust pH, and the like. In another embodiment acompound or pharmaceutical composition of this invention is formulatedwith a poly(ortho ester), which may be an auto-catalyzed poly(orthoester) with any of a variable percentage of lactic acid in the polymericbackbone, and optionally one or more additional excipients. In oneembodiment, poly (D,L-lactide-co-glycolide) polymer (PLGA polymer) isemployed, preferably a PLGA polymer with a hydrophilic end group, suchas PLGA RG502H from Boehringer Ingelheim, Inc. (Ingelheim, Germany).Such formulations may be made, for example, by combining a compound ofthis invention in a suitable solvent, such as methanol, with a solutionof PLGA in methylene chloride, and adding thereto a continuous phasesolution of polyvinyl alcohol under suitable mixing conditions in areactor. In general, any of a number of injectable and biodegradablepolymers, which are preferably also adhesive polymers, may be employedin a time release injectable formulation. The teachings of U.S. Pat.Nos. 4,938,763, 6,432,438, and 6,673,767, and the biodegradable polymersand methods of formulation disclosed therein, are incorporated herein byreference. The formulation may be such that an injection is required ona weekly, monthly or other periodic basis, depending on theconcentration and amount of construct, the biodegradation rate of thepolymer, and other factors known to those of skill in the art.

Pharmaceutically Effective Amount

In general, the actual quantity of compound of this inventionadministered to a patient will vary between fairly wide ranges dependingupon the mode of administration, the formulation used, and the responsedesired. The dosage for treatment is administration, by any of theforegoing means or any other means known in the art, of an amountsufficient to bring about the desired effect. This may readily bedetermined by one of ordinary skill in the art through means such aspharmacokinetic studies, plasma half-life studies, dose escalationstudies, and the like. Thus a pharmaceutically effective amount includesan amount of a compound or pharmaceutical composition of this inventionthat is sufficient to induce the desired effect.

In general, the compounds of this invention are highly active, with doseresponses as low as 0.01 μg/kg, generally with optimal or peak doseresponses between about 0.01 μg/kg and 25 μg/kg, depending on thespecific compound and the route of administration. For example, thecompound can be administered at 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 50, 100,or 500 μg/kg body weight, depending on specific compound selected, thedesired response, the route of administration, the formulation and otherfactors known to those of skill in the art. Conventional dose responsestudies and other pharmacological means may be employed to determine theoptimal dose for a desired effect with a given compound, givenformulation and given route of administration.

Combination Therapy and Weight Regulation

It is also possible and contemplated to use compounds of this inventionin combination with other drugs or agents for treatment of variousweight and feeding-related disorders. Compounds of this invention may beemployed for decreasing food intake and/or body weight in combinationwith any other agent or drug heretofore employed as a diet aid, or fordecreasing food intake and/or body weight. Compounds of this inventionmay further be employed for increasing food intake and/or body weight incombination with any other agent or drug heretofore employed forincreasing food intake and/or body weight.

Drugs that reduce energy intake include, in part, variouspharmacological agents, referred to as anorectic drugs, which are usedas adjuncts to behavioral therapy in weight reduction programs. Classesof anorectic drugs include, but are not limited to, noradrenergic andserotonergic agents. Noradrenergic medications may be described as thosemedications generally preserving the anorectic effects of amphetaminesbut with weaker stimulant activity. The noradrenergic drugs, except

phenylpropanolamine, generally act through a centrally mediated pathwayin the hypothalamus that causes anorexia. Phenylpropanolamine, a racemicmixture of norephedrine esters, causes a release of norepinephrinethroughout the body and stimulates hypothalamic adrenoreceptors toreduce appetite.

Suitable noradrenergic agents include, but are not limited to,diethylpropion such as TENUATE™ (1-propanone,2-(diethylamino)-1-phenyl-, hydrochloride) commercially available fromMerrell; mazindol (or5-(p-chlorophenyl)-2,5-dihydro-3H-imidazo[2,1-a]isoindol-5-ol) such asSANOREX™ commercially available from Novartis or MAZANOR™ commerciallyavailable from Wyeth Ayerst; phenylpropanolamine (or Benzenemethanol,alpha-(1-aminoethyl)-, hydrochloride); phentermine (or Phenol,3-[[4,5-duhydro-1H-imidazol-2-yl)ethyl](4-methylphenyl)amino],monohydrochloride) such as ADIPEX-P™ commercially available from Lemmon,FASTIN™ commercially available from Smith-Kline Beecham and Ionamin™commercially available from Medeva; phendimetrazine (or(2S,3S)-3,4-Dimethyl-2phenylmorpholine L-(+)-tartrate (1:1)) such asMETRA™ commercially available from Forest, PLEGINE™ commerciallyavailable from Wyeth-Ayerst; PRELU-2™ commercially available fromBoehringer Ingelheim, and STATOBEX™ commercially available from Lemmon;phendamine tartrate such as THEPHORIN™(2,3,4,9-Tetrahydro-2-methyl-9-phenyl-1H-indenol[2,1-c]pyridineL-(+)-tartrate (1:1)) commercially available from Hoffmann-LaRoche;methamphetamine such as DESOXYN™ Tablets ((S)—N,(alpha)-dimethylbenzeneethanamine hydrochloride) commercially availablefrom Abbott; and phendimetrazine tartrate such as BONTRIL™ Slow-ReleaseCapsules (-3,4-Dimethyl-2-phenylmorpholine Tartrate) commerciallyavailable from Amarin.

Suitable serotonergic agents include, but are not limited to,sibutramine such as MERIDIA™ capsules (a racemic mixture of the (+) and(−) enantiomers of cyclobutanemethanamine,1-(4-chlorophenyl)-N,N-dimethyl-(alpha)-(2-methylpropyl)-,hydrochloride, monohydrate) commercially available from Knoll,fenfluramine such as Pondimin™ (Benzeneethanamine,N-ethyl-alpha-methyl-3-(trifluoromethyl)-, hydrochloride) commerciallyavailable from Robbins; dexfenfluramine such as Redux™(Benzeneethanamine, N-ethyl-alpha-methyl-3-(trifluoromethyl)-,hydrochloride) commercially available from Interneuron. Fenfluramine anddexfenfluramine stimulate release of serotonin and inhibit its reuptake.Sibutramine inhibits the reuptake of serotonin, norepinephrine anddopamine, but does not stimulate secretion of serotonin.

Other serotonergic agents useful with the practice of the presentinvention include, but are not limited to, certain auoretic gene 5HT1ainhibitors (brain, serotonin) such as carbidopa and benserazide asdisclosed by U.S. Pat. No. 6,207,699 which is incorporated herein byreference; and certain neurokinin 1 receptor antagonist and selectiveserotonin reuptake inhibitors including fluoxetine, fluvoxamine,paroxtine, sertraline and other useful compounds as disclosed by U.S.Pat. No. 6,162,805, which is incorporated herein by reference. Otherpotential agents that may be employed include, for example, 5HT2cagonists.

Other useful compounds for reducing energy intake include, but are notlimited to, certain aryl-substituted cyclobutylalkylamines as disclosedby U.S. Pat. No. 6,127,424, which is incorporated herein by reference;certain trifluoromethylthiophenylethylamine derivatives as disclosed byU.S. Pat. No. 4,148,923, which is incorporated herein by reference;certain compounds as disclosed by U.S. Pat. No. 6,207,699, which isincorporated herein by reference; certain kainite or AMPA receptorantagonists as disclosed by U.S. Pat. No. 6,191,117, which isincorporated herein by reference; certain neuropeptide receptor subtype5 as disclosed by U.S. Pat. No. 6,140,354, which is incorporated hereinby reference; and certain alpha-blocking agents as disclosed by U.S.Pat. No. 4,239,763, which is incorporated herein by reference.

Moreover, several peptides and hormones regulate feeding behavior. Forexample, cholecystokinin and serotonin act to decrease appetite and foodintake. Leptin, a hormone produced by fat cells, controls food intakeand energy expenditure. In obese persons who are losing weight withoutmedications, a decrease in weight is associated with a decrease incirculating levels of leptin, suggesting its role in weight homeostasis.Obese patients with high leptin levels are thought to have peripheralleptin resistance secondary to the down-regulation of leptin receptors.Non-limiting examples of useful compounds affecting feeding behaviorinclude certain leptin-lipolysis stimulated receptors as disclosed by WO01/21647, which is incorporated herein by reference; certainphosphodiesterase enzyme inhibitors as disclosed by WO 01/35970, whichis incorporated herein by reference; certain compounds having nucleotidesequences of the mahogany gene as disclosed by WO 00/05373, which isincorporated herein by reference; and certain sapogenin compounds asdisclosed by U.S. Pat. No. 4,680,289, which is incorporated herein byreference.

Other useful compounds include certain gamma peroxisome proliferatoractivated receptor (PPAR) agonists as disclosed by WO 01/30343 and U.S.Pat. No. 6,033,656, which are incorporated herein by reference andcertain polypeptides such as fibroblast growth factor-10 polypeptides asdisclosed by WO 01/18210, which is incorporated herein by reference.

Moreover, monoamine oxidase inhibitors that decrease energy intake orincrease energy expenditure are useful with the practice of the presentinvention. Suitable, but non-limiting, examples of monoamine oxidaseinhibitors include befloxatone, moclobemide, brofaromine, phenoxathine,esuprone, befol, toloxatone, pirlindol, amiflamine, sercloremine,bazinaprine, lazabemide, milacemide, caroxazone and other certaincompounds as disclosed by WO 01/12176, which is incorporated herein byreference.

Certain compounds that increase lipid metabolism are also useful withthe practice of the present invention. Such compounds include, but arenot limited to, evodiamine compounds as disclosed by U.S. Pat. No.6,214,831, which is incorporated herein by reference.

Nutrient partitioning agents and digestive inhibitors are anotherstrategy in the treatment of obesity by interfering with the breakdown,digestion or absorption of dietary fat in the gastrointestinal tract.Gastric and pancreatic lipases aid in the digestion of dietarytriglycerides by forming them into free fatty acids that are thenabsorbed in the small intestine. Inhibition of these enzymes leads toinhibition of the digestion of dietary triglycerides. Non-limitingexamples include a lipase inhibitor, orlistat, such as XENICAL™ capsules((S)-2-formylamino-4-methyl-pentanoic acid (S)-1-[[(2S,3S)-3-hexyl-4-oxo-2-oxetanyl]methyl]-dodecyl ester) commerciallyavailable from Roche Laboratories and certain benzoxazinone compounds asdescribed by WO 00/40247, which is incorporated herein by reference.Agents that increase energy expenditure are also referred to asthermogenic medications. Non-limiting examples of suitable thermogenicmedications include xanthines, such as caffeine and theophylline,selective β-3-adrenergic agonists, for example certain compounds in U.S.Pat. No. 4,626,549, which is incorporated by reference herein, andα-2-adrenergic and growth hormones compounds as described in U.S. Pat.Nos. 4,937,267 and 5,120,713, which are incorporated by referenceherein.

Generally, a total dosage of the above-described obesity control agentsor medications, when used in combination with a compound of thisinvention can range from 0.1 to 3,000 mg/day, preferably from about 1 to1,000 mg/day and more preferably from about 1 to 200 mg/day in single or2-4 divided doses. The exact dose, however, is determined by theattending clinician and is dependent on such factors as the potency ofthe compound administered, the age, weight, condition and response ofthe patient.

Agents or drugs employed for increasing food intake and/or body weightinclude appetite stimulants such as megestrol acetate, adrenocorticoidssuch as prednisolone and dexamethasone, cyproheptidine, serotonergicdrugs such as fenfluramine, neuropeptide Y, and androgen antagonistssuch as flutamide, nilutamide, and zanoterone.

Assays and Animal Models

Selected compounds were tested in assays to determine binding andfunctional status, and were tested in animal models of feeding behavioras discussed below. The following assays and animal models wereemployed, with modifications as discussed in the examples.

Competitive Inhibition Assay Using [I¹²⁵]-NDP-α-MSH

A competitive inhibition binding assay was performed using membranehomogenates prepared from HEK-293 cells that express recombinant hMC4-R,hMC3-R, or hMC5-R, and from B-16 mouse melanoma cells (containingendogenous MC1-R). In some instances, HEK-293 cells that expressrecombinant hMC1-R were employed. In the examples that follow, allMC3-R, MC4-R and MC5-R values are for human recombinant receptors. MC1-Rvalues are for B-16 mouse melanoma cells, unless the heading is“hMC1-R”, in which case the value is for human recombinant MC1-R. Assayswere performed in 96 well GF/B Millipore multiscreen filtration plates(MAFB NOB10) pre-coated with 0.5% bovine serum albumin (Fraction V).Membrane homogenates were incubated with 0.2 nM (for hMC4-R) 0.4 nM (forMC3-R and MC5-R) or 0.1 nM (for mouse B16 MC1-R or hMC1-R)[I¹²⁵]-NDP-α-MSH (Perkin Elmer) and increasing concentrations of testcompounds in buffer containing 25 mM HEPES buffer (pH 7.5) with 100 mMNaCl, 2 mM CaCl₂, 2 mM MgCl₂, 0.3 mM 1,10-phenanthroline, and 0.2%bovine serum albumin. After incubation for 60 minutes at 37° C., theassay mixture was filtered and the membranes washed three times withice-cold buffer. Filters were dried and counted in a gamma counter forbound radioactivity. Non-specific binding was measured by inhibition ofbinding of [I¹²⁵]-NDP-α-MSH in the presence of 1 μM NDP-α-MSH. Maximalspecific binding (100%) was defined as the difference in radioactivity(cpm) bound to cell membranes in the absence and presence of 1 μMNDP-α-MSH. Radioactivity (cpm) obtained in the presence of testcompounds was normalized with respect to 100% specific binding todetermine the percent inhibition of [I¹²⁵]-NDP-α-MSH binding. Each assaywas conducted in triplicate and the actual mean values are described,with results less than 0% reported as 0%. Ki values for test compoundswere determined using Graph-Pad Prism® curve-fitting software.

Competitive Binding Assay Using [I¹²⁵]-AgRp (83-132)

Competitive binding studies using [I¹²⁵]-AgRP (83-132) were carried outusing membrane homogenates isolated from cells that express hMC4-R. Theassays were performed in 96-well GF/B Millipore multiscreen filtrationplates (MAFB NOB10) pre-coated with 0.5% bovine serum albumin (FractionV). The assay mixture contained 25 mM HEPES buffer (pH 7.5) with 100 mMNaCl, 2 mM CaCl₂, 2 mM MgCl₂, 0.3 mM 1,10-phenanthroline, 0.5% bovineserum albumin, membrane homogenates, radioligand [I¹²⁵]-AgRP (83-132)(Perkin Elmer) and increasing concentrations of compounds in a totalvolume of 200 μL. Binding was measured at radioligand concentrations of0.2 nM. After incubating for 1 hour at 37° C., the reaction mixture wasfiltered and washed with assay buffer containing 500 mM NaCl. The drieddiscs were punched out from the plate and counted on a gamma counter.The total binding of the radioligand did not exceed 10% of the countsadded to the reaction mixture. Ki values for test compounds weredetermined using Graph-Pad Prism® curve-fitting software.

Assay for Agonist Activity

Accumulation of intracellular cAMP was examined as a measure of theability of the test compounds to elicit a functional response in HEK-293cells that express MC4-R. Confluent HEK-293 cells that expressrecombinant hMC4-R were detached from culture plates by incubation inenzyme-free cell dissociation buffer. Dispersed cells were suspended inEarle's Balanced Salt Solution containing 10 mM HEPES (pH 7.5), 1 mMMgCl₂, 1 mM glutamine, 0.5% albumin and 0.3 mM3-isobutyl-1-methyl-xanthine (IBMX), a phosphodiesterase inhibitor. Thecells were plated in 96-well plates at a density of 0.5×10⁵ cells perwell and pre-incubated for 30 minutes. Cells were exposed for 1 hour at37° C. to test compounds dissolved in DMSO (final DMSO concentration of1%) at a concentration range of 0.05-5000 nM in a total assay volume of200 μL. NDP-α-MSH was used as the reference agonist. At the end of theincubation period, cells were disrupted by the addition of 50 μL oflysis buffer (cAMP EIA kit, Amersham) followed by vigorous pipetting.Levels of cAMP in the lysates were determined using a cAMP EIA kit(Amersham). Data analysis was performed by nonlinear regression analysiswith Graph-Pad Prism® software. The maximum efficacies of the testcompounds were compared to that achieved by the reference melanocortinagonist NDP-αMSH.

Food Intake and Body Weight After IN and IP Dosing

Changes in food intake and body weight were evaluated for selectedcompounds. Male C57BL/6 mice were obtained from Jackson labs (BarHarbor, Me.). Animals were individually housed in conventionalplexiglass hanging cages and maintained on a controlled 12 hour on/offlight cycle. Water and pelleted (Harlan Teklad 2018 18% Protein RodentDiet) food was provided ad libitum. The mice were dosed IP (byintraperitoneal injection) after a 24 hour fast or IN (by intranasaladministration) with vehicle or selected compounds (0.1-3 mg/kg, and insome cases up to 10 mg/kg). All animals were dosed once a day (or up tofour consecutive days) at the start of the “lights off” period. Thechanges in food intake for the 4 hour and 20 hour period after dosingrelative to control animals administered vehicle were determined. Bodyweights were determine 4 hours prior to dosing and 20 hours afterdosing, and the change in body weight relative to control animalsadministered vehicle were determined.

Determination of Mass and Nuclear Magnetic Resonance Analysis

The mass values were determined using a Waters MicroMass ZQ deviceutilizing a positive mode. Mass determinations were compared withcalculated values and expressed in the form of mass weight plus one (M+1or M+H).

Proton NMR data was obtained using a Bruker 300 MHz spectrometer. Thespectra were obtained after dissolving compounds in a deuteriatedsolvent such as chloroform, DMSO, or methanol as appropriate.

Synthetic Methods of the Invention

One general strategy includes developing a linear intermediate usingchiral building blocks such as amino acid derivatives. The linearintermediate can be cyclized using a Mitsunobo reaction strategy or byspontaneous cyclization through reactive groups such as a reactionbetween an amine and an ester or between an amine and an aldehydefunction. In these cyclizations, the driving force for intramolecularreaction versus intermolecular reaction is the thermodynamically favoredreaction forming a six-membered ring structure. In many instances, themethodology incorporates conditions that do not involve inversion orracemization of chiral centers. In some instances where a smallpercentage of racemate is observed, such as in use of an α-aminoaldehyde in certain positions, the desired chiral product is easilypurified by methods known in the art, such as flash chromatography on asilica gel column.

The group containing the Q ring can be made by use of an aldehydederivative of a D-amino acid. By use of an a-amino aldehyde theresulting group has, in its most basic form, the general structure:

By way of example, where an aldehyde derivative of D-Phe is employed insynthesis, in the resulting compound z is 1, and Q is phenyl. However,it can readily be seen that any D-amino acid listed above may beemployed as an aldehyde derivative, and may further be seen that one orboth hydrogen atoms in the —NH₂ may be substituted by an amine cappinggroup. In synthesis, preferably an N-protected D-amino acid aldehyde isemployed, where the N-protecting group is conventionally Boc or Fmoc.Because of the inherent instability of an α-amino aldehyde in solution,these compounds are preferably synthesized immediately prior to use. Twodifferent methods are used for synthesis.

In the first method, to an N-protected amino acid (such as with a Boc-or Fmoc-group) in dichloromethane was added TBTU (1 eq.) (here andelsewhere “eq.” is an abbreviation for equivalent or equivalents, as thecontext requires) and NMM (1 eq.). The mixture was stirred for half anhour and N,O-dimethylhydroxylamine hydrochloride (1 eq.) and NMM (1 eq.)were added. The reaction was carried out overnight. The solvent wasremoved and EtOAc was added. The organic phase was washed by aqueoussodium bicarbonate, brine and dried over sodium sulfate. Afterevaporation of solvent and drying under vacuum the residue was dissolvedin THF under nitrogen at −78° C. To this solution was added LAH (1 M inTHF, 1.5 eq.) slowly. The solution was stirred for an additional halfhour. The reaction was diluted by ether and quenched by aqueouspotassium hydrogen sulfate. The organic phase was washed with 1 N HCl,water, brine and dried over sodium sulfate. After removal of solvent thealdehyde was used immediately for the next step reaction withoutpurification.

In the second method, to an N-protected amino acid (such as with a Boc-or Fmoc-group) in THF was added borane-THF (1 M, 1.2 eq.) slowly at 0°C. The temperature was raised to room temperature and the solutionstirred for 2 hours. The reaction was quenched by 1 N HCl and thesolvent was evaporated. The crude product was purified on a silica gelcolumn to give a pure N-protected amino alcohol. This alcohol wasdissolved in dry dichloromethane and Dess-Martin periodinane (1.1 eq.)was added. The solution was stirred for 1 hour and the reaction wasdiluted by ether. The organic phase was washed by saturated sodiumbicarbonate with 10% sodium thiosulfate, then water, then brine anddried over sodium sulfate. After removal of solvent the crude productwas used for the next step reaction immediately without furtherpurification.

In the synthetic methods employed, either of the foregoing methods maybe employed to utilize a D-amino acid aldehyde.

In general, the synthetic methods employed were modifications of thosedescribed in applications cited above, including specifically patentapplication Ser. No. 10/837,519, but employing an amino acid aldehyde,and in most instances a D-amino acid aldehyde.

Fmoc-Lys(Trt)-OH was partially dissolved in DCM. To this mixture wasadded TBTU (1.1 eq.) and NMM (1.5 eq.). After this mixture was stirredat room temperature under nitrogen for 45 minute, and NH₂—CH(R²)—COOMe(i.e. H-D-Leu-OMe.HCl) (1.05 eq.) and NMM (1.1 eq.) were added. Thereaction was carried out at room temperature overnight.

The solvent was evaporated and the residue was partitioned between EtOAcand water. The organic layer was washed by 1 N HCl, saturated NaHCO₃ ,water and dried over sodium sulfate. After removal of solvent, product1.1 was obtained and was used for next step reaction without furtherpurification.

Compound 1-1 was dissolved in 30% Et₂NH in EtOAc. The solution wasstirred at room temperature for 2 hours. The solvent was removed. Thecrude product 1-2 was used for next step reaction without furtherpurification.

Compound 1-2 was partially dissolved in dry DMF. The mixture was heatedat 90° C. under nitrogen for three days. The reaction was stopped andDMF was removed under vacuum. This crude product was purified on silicagel column eluted with EtOAc/heptane (1:1), DCM, and subsequentlyMeOH/DCM (9:1). The final product 1-3 was collected after evaporation ofsolvent.

Compound 1-3 was suspended in THF at 0° C. under nitrogen. To thissuspension was added LAH (3.5 eq.) dropwise. The suspension became aclear solution after addition of LAH was completed. The reaction wasstirred at room temperature for 45 minutes and refluxed overnight. Thereaction mixture was quenched by addition of water, 15% NaOH and water,in sequence at 0° C. The mixture was stirred for 20 minutes at roomtemperature. The solid was removed by filtration and washed with ether,with ether evaporated to give the crude product 1-4.

Compound 1-4 was dissolved in THE. To this solution benzyl chloroformate(3 eq.) was added, and followed by water and sodium bicarbonate (5 eq.).The reaction mixture was stirred at room temperature for 3 hours. Tothis mixture water and EtOAc was added. The organic layer was separatedand washed by water till the aqueous layer reached neutral pH. Theorganic layer was dried over sodium sulfate. The solvent was evaporatedand the residue was purified on silica gel column eluted withEtOAc/heptane (1:4) to give product 1-5.

Compound 1-5 was dissolved in a solution of 5% TFA/1% TIS/DCM, and themixture stirred for 1 hour. The reaction mixture was diluted with DCM.The organic phase was washed with saturated sodium bicarbonate, water,brine and dried over sodium sulfate. After evaporation of solvent thecrude product 1-6 was used for next step reaction.

Compound 1-6 was dissolved in DCM. To this solution was added pyridine(10 eq.), and then 2-nitrobenzenesulfonyl chloride (2 eq.) slowly at 0°C. The temperature was raised to room temperature and stirred overnight.The solvent was removed. The residue was dissolved in EtOAc, which waswashed by 1N HCl, water, brine and dried over sodium sulfate. Afterremoval of solvent, the residue was purified on silica gel column elutedwith 25% EtOAc in heptane. After removal of solvent, compound 1-7 wasobtained.

Compound 1-7, TPP (3 eq.) and N-Boc-2-hydroxy-ethylamine (3 eq.) weredissolved in dry toluene. To this solution was added DIAD (3 eq.) intoluene at 0° C. The temperature was raised to room temperature after 30minutes and the solution was stirred overnight. The solvent was removedand the residue purified on silica gel column eluted with 50% EtOAc inheptane. Compound 1-8 was obtained after removal of solvent.

Compound 1-8 was dissolved in dry acetonitrile. To this solution wasadded potassium carbonate (6 eq.) and 4-mercaptophenol (4.5 eq.). Themixture was stirred overnight at room temperature. The solvent wasremoved, and the residue partitioned with EtOAc and water. The organiclayer was separated and washed by water, brine and dried over sodiumsulfate. The crude compound 1-9 was used for next step reaction.

Compound 1-9 was dissolved in THF/water (2:1). To this solution sodiumbicarbonate (5 eq.) and di-t-butyl carbonate (2 eq.) were addedsubsequently. The mixture was stirred overnight at room temperature.After removal of THF, EtOAc was added to extract the product. Theorganic layer was washed with 1 N HCl, water, brine and dried oversodium sulfate. The solvent was removed and the residue purified onsilica gel column eluted with 25% EtOAc in heptane. Product 1-10 wasobtained after removal of solvent.

Compound 1-10 was treated with catalytic amounts of Pd on carbon inethanol under hydrogen (1 atm.) overnight at room temperature. Afterfiltration through a Celite pad, the solvent was removed. The crudeproduct was dried under vacuum and it was used for next step reactionwithout further purification.

Q-COOH (i.e. Boc-D-2-Naphthylalanine) (4 eq.), EDC (4 eq.) and HOAt (4eq.) were dissolved in DMF. The mixture was stirred at 0° C. for 30minutes. To this solution was added Compound 1-10 in one portion. Thereaction was carried out overnight at room temperature. The solvent wasremoved and the residue was purified on silica gel column to giveproduct 1-11.

Compound 1-11 was treated with TFA for 3 hours at room temperature.After removal of solvent the residue was purified by HPLC to giveproduct 1-12.

A mixture of Cbz-Glu(OtBu)-OH, TBTU (1.1 eq.) and NMM (1.5 eq.) in 100mL of DCM were stirred at room temperature under nitrogen for 30minutes. To the solution were added NH₂—CH(R²)—COOMe in hydrochloridesalt (1.05 eq.) and NMM (1.13 eq.). The mixture was stirred at roomtemperature overnight. The solvent was removed and the residue wasdissolved in 250 mL EtOAc. The organic solvent was washed with water, 1N HCl, saturated aqueous sodium bicarbonate solution, water and driedover sodium sulfate. After removal of solvent, the product (2-1) wasused for the next step reaction without further purification.

Compound 5-1 was dissolved in EtOAc. It was subject to the treatmentwith hydrogen at 1 atm. in the presence of Pd/C at room temperature forthree days. The reaction mixture was filtered through a Celite pad,which was then washed with methanol. The solvent removed and the product2-2 was used for the next step reaction without purification.

Compound 2-2 was dissolved in DMF. The solution was heated at 90° C. forthree days. The solvent was removed and the residue was dissolved inDCM, which was washed with 1 N HCl. The organic layer was separated anddried over sodium sulfate. After solvent removal, product 2-3 wasobtained.

A suspension of compound 2-3 in THF was stirred at 0° C. To thesuspension was added lithium aluminum hydride (4.6 eq.). The mixture wasstirred for 25 minutes at 0° C. and 4 hours at room temperature and thenrefluxed under nitrogen overnight. The reaction was quenched by theaddition water, 15% sodium hydroxide and water at 0° C. The mixture wasstirred at room temperature for an additional 30 minutes. The solid wasremoved by filtration and washed with ether. The solvent was removed anddried under vacuum to give the crude compound 2-4.

Compound 2-4 was dissolved in THF. To this solution was added benzylchloroformate (2.5 eq.) followed by water and sodium bicarbonate (6eq.), such that the ratio of THF to water was 2 to 1. The mixture wasstirred overnight at room temperature. To this mixture were added EtOAcand water. The organic layer was washed with water and dried over sodiumsulfate. The solvent was removed and the residue was dissolved inmethanol and 1 N sodium hydroxide (3 eq.). The reaction was carried outat room temperature for three days. The solvent was removed and theresulted residue was dissolved in EtOAc. The organic phase was washedwith 1 N HCl, water, aqueous sodium bicarbonate and dried over sodiumsulfate. The solvent was removed and the residue purified on a silicagel column to give product 2-5.

Compound 2-5 was dissolved in DCM. To this solution was addedDess-Martin periodinane (1.2 eq.). The reaction was continued at roomtemperature for 1.5 hours. Ether was added to dilute the mixture and thereaction was quenched by addition of a solution of sodium thiosulfate insaturated sodium bicarbonate. The organic layer was washed with the samesolution and dried over sodium sulfate. After removal of solvent thecrude product 2-6 was used for next step reaction without furtherpurification.

To a solution of compound 2-6 and N-Boc-ethylenediamine (1.05 eq.) inTHF was added molecular sieves. The mixture was stirred for 3 hours atroom temperature. To this mixture was added sodium triacetoxyborohydride(1.5 eq.). The reaction mixture was stirred at room temperatureovernight, and the solid removed by filtration. After the solvent wasremoved the residue was partitioned between EtOAc and water, the organiclayer separated and the water layer extracted with EtOAc. The combinedorganic layer was dried over sodium sulfate. After removal of solventthe residue was dissolved in THF and water (v:v=2:1). To this solutionwere added di-t-butyl dicarbonate (1.2 eq.) and sodium bicarbonate (5eq.). The mixture was stirred overnight at room temperature. EtOAc wasadded and the organic layer was washed with water and dried over sodiumsulfate. After removal of solvent the residue was purified on silica gelcolumn to give product 2-7.

Compound 2-7 was dissolved in ethanol and treated with hydrogen underatmosphere pressure in the presence of a catalytic amount of Pd/C. Thereaction was carried out overnight at room temperature. The solid wasfiltered and washed with ethanol several times. The solvent was removedto give product 2-8.

To a solution of Q-COOH (4 eq.) in DMF was added HOAT (4 eq.) and EDC (4eq.) at 0° C. After the mixture was stirred for 30 minutes, compound 2-8was added to this mixture. The reaction was continued overnight at roomtemperature. The solvent was removed and the residue was purified on asilica gel column to give product 2-9.

Compound 2-9 was treated by TFA for three hours at room temperature.After removal of solvent, the residue was purified by HPLC to givecompound 2-10.

According to a further aspect of the invention, there is provided amethod of making a compound of formula of structure III:

wherein each R¹ is the same, such that the compound of structure issymmetric with respect to R¹, where R¹ is of the formula

-   a is an index value from 0 to 2;-   b is an index value from 0 to 4;-   R⁸ is H or ═O;-   R⁹ is H or N(R^(10a))(R^(10b));-   R^(10a) and R^(10b) are each independently hydrogen, acetyl, methyl,    ethyl, propyl, isopropyl, butyl, pentyl, hexyl, isobutyl, benzyl,    benzoyl, hexanoyl, propionyl, butanoyl, pentanoyl, heptanoyl,    cyclopropyl, cyclopropylmethyl, cyclobutyl, cyclobutylmethyl,    cyclohexyl, cyclohexylmethyl, or polyethylene glycol;-   Q is an aromatic carbocyclic ring selected from the group consisting    of phenyl, substituted phenyl, naphthyl and substituted naphthyl;    one of R^(2x) and R^(2y) is a C₁ to C₆ aliphatic linear or branched    chain,

and the remaining of R^(2x) and R^(2y) is hydrogen; and

-   c is an index value from 0 to 4;    the method comprising the steps of:-   (1) providing a precursor of formula IV:

wherein Pg¹ is a first protecting group;

-   (2) reacting the precursor of formula IV with at least two    equivalent proportions of an amino acid residue comprising at least    one aromatic carbocyclic ring selected from the group consisting of    phenyl, substituted phenyl, naphthyl and substituted naphthyl; and-   (3) removing the first protecting group Pg¹ and any other protecting    group.

In one aspect, the compound of formula IV can be a compound of formulaV:

Providing a precursor of formula IV:

can include providing a precursor of formula VI:

wherein Pg² is a second protecting group orthogonal to Pg¹; andselectively removing the second protecting groups Pg².

In the above-described method, the amino acid residue comprising atleast one aromatic carbocyclic ring is a D-amino acid. The D-amino acidmay be a protected D-2-naphthylalanine. The D-amino acid may be aprotected D-phenylalanine, optionally wherein the phenyl ring includesone, two or three ring substituents, and when more than one is present,the ring substituents are the same or different and independentlyhydroxyl, halogen, alkyl, O-alkyl, aryl or O-aryl groups. Representativeamino acid residues comprising at least one aromatic carbocyclic ringinclude D-amino acids such as Nal 1, Nal 2, (N-Bzl)Nal 2, (N-PhEt)Nal 2,pF-Phe, Phe(4-Br), Phe(4-CF₃), Phe(4-Cl), Phe(3-Cl), Phe(2-Cl),Phe(2,4-diCl), Phe(3,4-diCl), Phe(5-Cl), Phe(2-Cl, 4-CF₃), Phe(2-Cl,4-Me), Phe(3,4-diF), Phe(2-F, 4-Cl), Phe(2,4-diF), Phe(4-I), Phe(4-Me),Phe(2,4-diMe), Phe(4-OMe), Phe(3,4-di-OMe), Phe(2-Me, 4-Cl), Phe(4-NC),Phe(4-NO₂), Phe(4-Phenyl), or Phg. In the method, the amino acid residuecomprising at least one aromatic carbocyclic ring may be a protectedamino acid residue, such as where the protecting group is Pg₂. In arelated aspect, the amino acid residue including at least one aromaticcarbocyclic ring may be a D-beta-amino acid.

In the method, reacting the precursor of formula IV with at least twoequivalent proportions of an amino acid residue comprising at least onearomatic carbocyclic ring can include reacting the precursor of formulaIV with at least two equivalent proportions of the amino acid residue ina solution of N,N-dimethylformamide comprising(1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride) and1-hydroxy-7-azabenzotriazole. Alternatively, the precursor of formula IVcan be reacted with approximately four equivalent proportions of each ofthe amino acid residue, (1-ethyl-3-[3-dimethylaminopropyl]carbodiimidehydrochloride) and 1-hydroxy-7-azabenzotriazole in a solution ofN,N-dimethylformamide.

In the above-described method, the compound of formula V can be made bya method comprising the steps of:

-   -   reacting Fmoc-Lys(Trt)-OH with H-D-Leu-OMe HCl in an inert        solvent containing        2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium        tetrafluoroborate and N-methyl-morpholine to yield a crude        product of formula VII:

-   -   cyclizing the product of formula VII by heating the product of        formula VII in dry N,N-dimethylformamide and recovering the        product of formula VIII:

-   -   removing the keto groups of the product of formula VIII by a        reduction reaction and introducing benzyloxycarbonyl (Cbz)        protecting groups to protect the piperazine ring nitrogens and        recovering the product of formula IX:

-   -   modifying the TrtNH group by selectively removing the Trt group,        adding a third protecting group in lieu of the Trt group,        reacting the resulting compound with N-Boc-2-hydroxy-ethylamine,        removing the third protecting group, reacting the product with        di-t-butyl carbonate in a solution comprising sodium bicarbonate        and recovering a product of formula X:

-   -   removing the Cbz protecting groups by incubation of the product        of formula X in a catalytic amount of palladium on carbon in        ethanol;    -   wherein Pg₁ is Boc. In this method, the reduction reaction can        include lithium aluminum hydride. Introducing Cbz protecting        groups can include a reaction in tetrahydrofuran with benzyl        chloroformate.

In the above-described method of making a compound of formula ofstructure III, where substituted, each Q ring may be substituted withone or more ring substituents selected from the group consisting ofhydroxyl, halogen, sulfonamide, alkyl, O-alkyl, aryl, O-aryl andcombinations thereof.

Representative Compounds of the Invention

EXAMPLE 1(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[3-(2-minoethylamino)propyl]-2-isobutylpiperazin-1-yl}-3-(2,4-dichlorophenyl)propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-D-2,4-dichlorophenylalanine as Q-COOH, and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 672.3(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 23% 41% 89% 55%Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 309 574 44 ND

In mouse model IN feeding studies at a 0.1 and 0.3 mg/kg dose level, anaverage decrease in body weight of 0.7% and 3.1%, respectively, comparedto control animals was observed at 20 hours.

EXAMPLE 2(R)-2-Amino-1-[(2R,5S)-5-[3-(2-aminoethylamino)propyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-D-2′-naphthylalanine acid as Q-COOH and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 636.6(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 40% 79% 96% 57%Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 135 127 13 ND

In mouse model IN feeding studies at a 0.1, 0.3 and 1 mg/kg dose level,an average decrease in body weight of 1%, 3% and 3.2%, respectively,compared to control animals was observed at 20 hours.

EXAMPLE 3(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-cyclohexylmethylpiperazin-1-yl}-3-(2,4-dimethyl-phenyl)propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-2,4-dimethylphenylalanine as Q-COOH and D-cyclohexylalamine asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 632.8(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 35 22 83 43 Ki(nm) (NDP-α-MSH) MC1-R MC3-R MC4-R MC5-R — — 81 —

EXAMPLE 4(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]5-[3-(2-aminoethylamino)propyl]-2-cyclohexylmethylpiperazin-1-yl-}3-(2,4-dichlorophenyl)-propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-2,4-dichlorophenylalanine as Q-CO₂H and D-cyclohexylalamine asNH₂—CH(R²)—CO₂Me. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 712.6(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 27% 36% 83% 31%Ki (nm) (NDP-α-MSH) MC1-R MC3-R MC4-R MC5-R ND ND 74 ND

EXAMPLE 5(R)-2-Amino-1-[(2R,5S)-5-[3-(2-aminoethylamino)propyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-cyclohexylmethylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-D-2′-naphthylalanine acid as Q-CO₂H and D-cyclohexylalamine asNH₂—CH(R²)-CO₂Me. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 676.6(M+H).

Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 22 36 81 30 Ki (nm)(NDP-α-MSH) MC1-R MC3-R MC4-R MC5-R — — 99 —

EXAMPLE 6(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-2-[3-(2-aminoethylamino)propyl]-5-isobutylpiperazin-1-yl}-3-(2,4-dimethylphenyl)propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-2,4-dimethylphenylalanine as Q-COOH and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 592.9(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 22% 14% 83% 38%Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R ND ND 60 ND

EXAMPLE 7(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-(2,4-dichlorophenyl)propan-1-one

The following compound was synthesized by the method of Scheme 1 usingBoc-2,4-dichlorophenylalanine as Q-COOH and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 687(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 36% 59% 97% 47%Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 754 327 36 296

EXAMPLE 8(R)-2-Amino-1-[(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one

The following compound was synthesized by the method of Scheme 1 usingBoc-D-2′-naphthylalanine acid as Q-COOH and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 651.3(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 68% 62% 99% 49%Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 215 321 9 253

In mouse model IN feeding studies in fed animals at a 0.1 and 0.3 mg/kgdose level, an average decrease in body weight of 1.2%, and 3%,respectively, compared to control animals was observed at 20 hours.

EXAMPLE 9(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-(2,4-dimethylphenyl)propan-1-one

The following compound was synthesized by the method of Scheme 1 usingBoc-2,4-dimethyl-phenylalanine as Q-COOH and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 607.4(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 39% 55% 95% 51%Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 567 1047 83 450

EXAMPLE 10(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(3,4-dichlorophenyl)propionyl]-2-[-4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(3,4-dichlorophenyl)propan-1-one

The following compound was synthesized by the method of Scheme 1 usingBoc-3,4-dichlorophenylalanine as Q-COOH and D-Leu-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 687.2(M+H).

Ki (nm) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 116 69 4 179

In mouse model IN feed studies at a 0.1 and 0.3 mg/kg dose level, anaverage decrease in body weight of 0.6% and 4.9%, respectively, comparedto control animals was observed at 20 hours.

EXAMPLE 11(R)-2-Amino-1-[(2S,5R)-2-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-5-cyclohexylmethylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one

The following compound was synthesized by the method of Scheme 1 usingBoc-D-2′-naphthylalanine as Q-COOH and D-Cyclohexylalanine asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 691.3(M+H).

Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 153 435 20 103

In mouse model IN feed studies at a 0.1 and 0.3 mg/kg dose level, anaverage decrease in body weight of 1.6% and 2.6%, respectively, comparedto control animals was observed at 20 hours.

EXAMPLE 12(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-cyclohexylmethylpiperazin-1-yl}-3-(2,4-dichlorophenyl)-propan-1-one

The following compound was synthesized by the method of Scheme 1 usingBoc-2,4-dichlorophenylalanine as Q-CO₂H and D-cyclohexylalanine asNH₂—CH(R²)—CO₂Me. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 727(M+H).

Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 270 443 17 139

EXAMPLE 13(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-methylpiperazin-1-yl}-3-(2,4-dichlorophenyl)propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-2,4-dichlorophenylalanine as Q-COOH and D-Ala-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 631(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 67% 89% 98% 93%Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R ND ND 41 ND

EXAMPLE 14(R)-2-Amino-1-{-(2R,5S)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-methylpiperazin-1-yl}-3-(2,4-dimethylphenyl)propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-2,4-dimethylphenylalanine as Q-COOH and D-Ala-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 551.3(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 53% 57% 96% 76%Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R ND ND 64 ND

EXAMPLE 15(R)-2-Amino-1-[(2R,5S)-5-[3-(2-aminoethylamino)propyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-methylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-D-2′-naphthylalanine acid as Q-COOH and D-Ala-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 595.2(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 62% 79% 93% 73%Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R ND ND 42 ND

EXAMPLE 16(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(3,4-dichlorophenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-methylpiperazin-1-yl}-3-(3,4-dichlorophenyl)propan-1-one

The following compound was synthesized by the method of Scheme 2 usingBoc-3,4-dichlorophenylalanine as Q-COOH and D-Ala-OMe asNH₂—CH(R²)—COOMe. Following purification, the compound was tested asdescribed above with the results shown. The mass was analyzed as 631(M+H).

Inhibition at 1 μM (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R 77% 94% 96% 84%Ki (nM) (NDP-α-MSH) hMC1-R MC3-R MC4-R MC5-R ND ND 19 ND

EXAMPLE 17(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(3,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-methylpiperazin-1-yl}-3-(3,4-dichlorophenyl)propan-1-one

The compound of Example 17 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Ala-OMe and Boc-D-3,4-di-Cl-Phe-OHwere used.

EXAMPLE 18(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-methylpiperazin-1-yl}-3-(2,4-dimethylphenyl)propan-1-one

The compound of Example 18 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Ala-OMe andBoc-D-3,4-di-methyl-Phe-OH were used.

EXAMPLE 19(R)-2-Amino-1-{(2S,5R)-2-[4-(2-aminoethylamino)butyl]-4-[(R)-2-amino-3-(4-trifluoromethylphenyl)propionyl]-5-isobutylpiperazin-1-yl}-3-(4-trifluoromethylphenyl)propan-1-one

The compound of Example 19 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-D-4-trifluromethyl-Phe-OH were used.

EXAMPLE 20(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(4-chlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(4-chlorophenyl)propan-1-one

The compound of Example 20 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-4-Cl-Phe-OH wereused.

EXAMPLE 21(R)-2-Amino-1-{(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-[(R)-2-amino-3-(3-trifluoromethylphenyl)propionyl]-2-isobutylpiperazin-1-yl}-3-(3-trifluoromethylphenyl)propan-1-one

The compound of Example 21 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-D-3-trifluromethyl-Phe-OH were used.

EXAMPLE 22 1-{(2R,5S)-5-[4-(2-Aminoethylamino)butyl]-4-[3-(3,4-dichlorophenyl)propionyl]-2-isobutylpiperazin-1-yl}-3-(3,4-dichlorophenyl)propan-1-one

The compound of Example 22 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and 3,4-di-Cl-propionic acidwere used.

EXAMPLE 23N¹-(4-{(2S,5R)-1,4-Bis-[3-(3,4-dichlorophenyl)propyl]-5-isobutylpiperazin-2-yl}-butyl)ethane-1,2-diamine

The compound of Example 23 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and 3,4-di-Cl-propionic acidwere used. The 3,4-di-Cl-propionic acid was converted to thecorresponding aldehyde for a reductive alkylation reaction.

EXAMPLE 24(R)-3-Amino-1{(2R,5S)-4-[(R)-3-amino-4-(2,4-dichlorophenyl)butyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-4-(2,4-dichlorophenyl)butan-1-one

The compound of Example 24 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-(R)-3-Amino-4-(2,4-dichlorophenyl)butyric acid were used.

EXAMPLE 25(R)-3-Amino-1-{(2S,5R)-4-[(R)-3-amino-3-(2,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(2,4-dichlorophenyl)propan-1-one

The compound of Example 25 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-(R)-3-Amino-3-(2,4-dichlorophenyl)propionic acid were used.

EXAMPLE 26(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(4-chloro-2-methylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(4-chloro-2-methylphenyl)propan-1-one

The compound of Example 26 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-D-2-methyl-4-chloro-Phe-OH were used.

EXAMPLE 27(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(2-chloro-4-methylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(2-chloro-4-methylphenyl)propan-1-one

The compound of Example 27 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-D-4-methyl-2-chloro-Phe-OH were used.

EXAMPLE 28(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(3,4-difluorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(3,4-difluorophenyl)propan-1-one

The compound of Example 28 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-3,4-di-F-Phe-OHwere used.

EXAMPLE 29(R)-2-Amino-1-[(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-4-phenyl-butyryl)-2-isobutylpiperazin-1-yl]-4-phenylbutan-1-one

The compound of Example 29 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-homo-Phe-OH wereused.

EXAMPLE 30(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(4-tert-butylphenyl)propionyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-(4-tert-butylphenyl)propan-1-one

The compound of Example 30 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-4-tBu-Phe-OH wereused.

EXAMPLE 311-{(2R,5S)-5-[4-(2-Aminoethylamino)butyl]-4-[3-(3,4-dimethylphenyl)propionyl]-2-isobutylpiperazin-1-yl}-3-(3,4-dimethylphenyl)propan-1-one

The compound of Example 31 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and 3,4-di-methyl-propionicacid were used.

EXAMPLE 32(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-([1,3,4]thiadiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 32 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 2-amino-1,3,4-thiadiazole.

EXAMPLE 33(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(3,4-dimethylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(3,4-dimethylphenyl)propan-1-one

The compound of Example 33 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-D-3,4-di-methyl-Phe-OH were used.

EXAMPLE 34(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(4-chloro-3-methylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(4-chloro-3-methylphenyl)propan-1-one

The compound of Example 34 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe andBoc-D-2-methyl-4-chloro-Phe-OH were used.

EXAMPLE 35(R)-2-Amino-1-{(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-[(R)-2-amino-3-(4-methoxyphenyl)propionyl]-2-isobutylpiperazin-1-yl}-3-(4-methoxyphenyl)propan-1-one

The compound of Example 35 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-4-methoxy-Phe-OHwere used.

EXAMPLE 36(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-biphenyl-4-yl-propionyl)-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-biphenyl-4-yl-propan-1-one

The compound of Example 36 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-4-phenyl-Phe-OHwere used.

EXAMPLE 37(R)-2-Amino-1-[(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-(3-[1,2,4]triazol-1-yl-propyl)piperazin-1-yl-3-naphthalen-2-yl-propan-1-one

The compound of Example 37 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 1,2,4-triazole.

EXAMPLE 38(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-([1,2,4]triazol-4-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 38 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 4-amino-4H-1,2,4-triazole.

EXAMPLE 39(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(thiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 39 was made by the methods of the Schemes 2 and3 described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. The method C in Scheme 5 was used forincorporation of 2-aminothiazole.

EXAMPLE 40(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(5-methylthiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 40 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 2-amino-5-methylthiazole.

EXAMPLE 41(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(4-methylthiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 41 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 2-amino-4-methylthiazole.

EXAMPLE 42(R)-2-Amino-{((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(5-methyl-[1,3,4thiadiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 42 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 2-amino-5-methyl-1,3,4-thiadiazole.

EXAMPLE 43N-{(R)-2-[(2S,5R)-4-((R)-2-Acetylamino-3-naphthalen-2-yl-propionyl)-5-isobutyl-2-(3-[1,2,4]triazol-1-yl-propyl)piperazin-1-yl]-1-naphthalen-2-ylmethyl-2-oxo-ethyl}-acetamide

The compound of Example 43 was derived from the compound of Example 37,in which the free amino groups were acetylated by the reaction of aceticanhydride with the compound of Example 37 in the presence of pyridine.

EXAMPLE 44(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(3-methylisoxazol-5-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 44 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 5-amino-3-methylisoxazole.

EXAMPLE 45(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(5-methylisoxazol-3-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 45 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 3-amino-5-methylisoxazole.

EXAMPLE 46(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(pyrimidin-4-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 46 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of aminopyrazine.

EXAMPLE 47(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(isoxazol-3-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 47 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 3-aminoisoxazole.

EXAMPLE 48(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(pyrimidin-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 83 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. Method C in Scheme 5 was used forincorporation of 2-aminopyrimidine.

EXAMPLE 49(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-5-[2-(1H-imidazol-2-yl)ethyl]-2-isobutylpiperazin-1-yl}-3-naphthalen-2-yl-propan-1-one

The compound of Example 49 was made by the methods of Schemes 2 and 3described above, in which Fmoc-Glu(OtBu)-OH, D-Leu-OMe andBoc-D-2-Nal-OH were used. The imidazole group was formed by Dess-Martinoxidation of hydroxyl group to aldehyde and subsequent reaction withglyoxal trimer and ammonium acetate in acetic acid under microwavecondition at 100° C. for 5 minutes.

EXAMPLE 50(S)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-2-isobutyl-5-[3-([1,3,4]thiadiazol-2-ylamino)propyl]piperazin-1-yl}-3-(2,4-dichlorophenyl)propan-1-one

The compound of Example 50 was made by the methods of Scheme 4 describedabove, in which Boc-L-2,4-di-CI-Phe-OH was used as QCOOH.

EXAMPLE 51(R)-2-Amino-1-[(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-3-p-tolyl-propionyl)-2-isobutylpiperazin-1-yl]-3-p-tolyl-propan-1-one

The compound of Example 51 was made by the methods of Scheme 1 describedabove, in which Fmoc-Lys(Trt)-OH, D-Leu-OMe and Boc-D-4-methyl-Phe-OHwere used.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/orsynthetic conditions of this invention for those used in the precedingexamples.

Although the invention has been described in detail with particularreference to these preferred embodiments, other embodiments can achievethe same results. Variations and modifications of the present inventionwill be obvious to those skilled in the art and it is intended to coverall such modifications and equivalents. The entire disclosures of allreferences, applications, patents, and publications cited above, and ofthe corresponding application(s), are hereby incorporated by reference.

1. A compound having the formula of structure I:

or an enantiomer, stereoisomer or diastereoisomer thereof, or apharmaceutically acceptable salt thereof, wherein one or two of R^(1a),R^(1b), R^(2a), and R^(2b) are independently a C₁ to C₆ aliphatic linearor branched chain and the remaining of R^(1a), R^(1b), R^(2a), andR^(2b) are hydrogen, provided that at least one of R^(1a) and R^(1b) andat least one of R^(2a) and R^(2b) are hydrogen; or one of R^(1a),R^(1b), R^(2a), and R^(2b) are

and the remaining of R^(1a), R^(1b), R^(2a), and R^(2b) are hydrogen; orR^(1a) and R^(1b) together form ═O and one of R^(2a) and R^(2b) is a C₁to C₆ aliphatic linear or branched chain,

and the remaining of R^(2a) and R^(2b) is hydrogen; y is in eachinstance an independent index value from 0 to 5; W is a diamineheteroatom unit with at least one cationic center, hydrogen bond donoror hydrogen bond acceptor; L² is a bond or (CH₂)_(z); z is an indexvalue from 1 to 6; X is CH₂, C═O or C═S; the groups—C(R⁸)(CH₂)_(v)CH(R⁹)(CH₂)_(y)-Q and —C(R⁸)(CH₂)_(v)CH(R⁹)(CH₂)_(y)-Jare the same and, in those groups, R⁸ is H or ═O; R⁹ is hydrogen orN(R^(10a))R^(10b); R^(10a) and R^(10b) are independently hydrogen,acetyl, methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl,isobutyl, benzyl, benzoyl, hexanoyl, propionyl, butanoyl, pentanoyl,heptanoyl, cyclopropyl, cyclopropylmethyl, cyclobutyl, cyclobutylmethyl,cyclohexyl, cyclohexylmethyl, or polyethylene glycol; v is an indexvalue from 0 to 2; and Q and J are the same and represent an aromaticcarbocyclic ring selected from the group consisting of phenyl,substituted phenyl, naphthyl and substituted naphthyl; wherein thecarbon atoms marked with an asterisk can have any stereochemicalconfiguration.
 2. The compound as claimed in claim 1, wherein R⁸ is ═O.3. The compound as claimed in claim 1, wherein Q is:

where R^(3a), R^(3b) and R^(3c) are optional ring substituentsindependently selected from hydroxyl, halogen, alkyl, —O-alkyl, aryl,and —O-aryl.
 4. The compound as claimed in claim 3, wherein at least oneof R^(3a), R^(3b) or R^(3c) is —CH₃ or —O—CH₃.
 5. The compound asclaimed in claim 3, wherein at least one of R^(3a), R^(3b) or R^(3c) is—Cl or —CF₃.
 6. The compound as claimed in claim 1 wherein W is selectedan amine, amide, alcohol, carboxylic acid, ether, ester, and urea.
 7. Acompound having the formula of structure II

or an enantiomer, stereoisomer or diastereoisomer thereof, or apharmaceutically acceptable salt thereof, wherein one or two of R^(1a),R^(1b), R^(2a), and R^(2b) are independently a C₁ to C₆ aliphatic linearor branched chain and the remaining of R^(1a), R^(1b), R^(2a), andR^(2b) are hydrogen, provided that at least one of R^(1a) and R^(1b) andat least one of R^(2a) and R^(2b) are hydrogen; or one of R^(1a),R^(1b), R^(2a), and R^(2b) are

and the remaining of R^(1a), R^(1b), R^(2a), and R^(2b) are hydrogen; orR^(1a) and R^(1b) together form ═O and one of R^(2a) and R^(2b) is a C₁to C₆ aliphatic linear or branched chain,

and the remaining of R^(2a) and R^(2b) is hydrogen; R^(4a) is NH,N(—(CH₂)_(y)—CH₃), NH—C(═O), or C(═O)—NH; R^(5a) is NH₂,NH—(CH₂)_(y)—CH₃, or N(—(CH₂)_(y)—CH₃)₂; y is in each instanceindependently an index value from 0 to 5; the groups—C(R⁸)CH(R⁹)(CH₂)_(y)-Q and —C(R⁸)CH(R⁹)(CH₂)_(y)-J are the same and, inthose groups R⁸ is H or ═O; R⁹ is hydrogen or N(R^(10a))R^(10b); R^(10a)and R^(10b) independently hydrogen, acetyl, methyl, ethyl, propyl,isopropyl, butyl, pentyl, hexyl, isobutyl, benzyl, benzoyl, hexanoyl,propionyl, butanoyl, pentanoyl, heptanoyl, cyclopropyl,cyclopropylmethyl, cyclobutyl, cyclobutylmethyl, cyclohexyl orcyclohexylmethyl; Q and J are the same and represent an aromaticcarbocyclic ring selected from the group consisting of phenyl,substituted phenyl, naphthyl and substituted naphthyl; and z is an indexvalue from 1 to 6; wherein the carbon atoms marked with an asterisk canhave any stereochemical configuration.
 8. A compound as claimed in claim1 or claim 7, wherein the compound is selected from: (R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-isobutylpiperazin-1-yl}-3-(2, 4-dichlorophenyl)propan-1-one;(R)-2-Amino-1-[(2R,5S)-5-[3-(2-aminoethylamino)propyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R, 5S)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-cyclohexylmethylpiperazin-1-yl}-3-(2,4-dimethylphenyl)propan-1-one; (R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-cyclohexylmethylpiperazin-1-yl}-3-(2,4-dichloro-phenyl)-propan-1-one; (R)-2-Amino-1-[(2R, 5S)-5-[3-(2-aminoethylamino)propyl]-4((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-cyclohexylmethylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-2-[3-(2-aminoethylamino)propyl]-5-isobutylpiperazin-1-yl}-3-(2, 4-dimethylpheny)-propan-1-one;(R)-2-Amino-1-{(2R, 5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-(2, 4-dichlorophenyl)propan-1-one;(R)-2-Amino-1-[(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R, 5S)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-(2, 4-dimethylphenyl)propan-1-one;(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(3,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(3 ,4-dichloropheny)-propan-1-one;(R)-2-Amino-1-[(2S,5R)-2-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-5-cyclohexylmethylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-cyclohexylmethylpiperazin-1-yl}-3-(2,4-dichloro-phenyl)propan-1-one; (R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-methylpiperazin-1-yl}-3-(2, 4-dichlorophenyl)-propan-1-one;(R)-2-Amino-1-{(2R, 5S)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-methylpiperazin-1-yl}-3-(2,4-dimethylphenyl)propan-1-one; (R)-2-Amino-1-[(2R,5S)-5-[3-(2-aminoethylamino)propyl]-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-methylpiperazin-1-yl]-3-naphthalen-2-yl-propan-1-one;and (R)-2-Amino-1-{(2R, 5S)-4-[(R)-2-amino-3-(3,4-dichlorophenyl)propionyl]-5-[3-(2-aminoethylamino)propyl]-2-methylpiperazin-1-yl}-3-(3, 4-dichlorophenyl)-propan-1-one, ora pharmaceutically acceptable salt thereof.
 9. A compound as claimed inclaim 1 or claim 7, wherein the compound is selected from:(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(3,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-methylpiperazin-1-yl}-3-(3, 4-dichlorophenyl)-propan-1-one;(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(2,4-dimethylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-methylpiperazin-1-yl}-3-(2, 4-dimethylphenyl)-propan-1-one;(R)-2-Amino-1-{(2S,5R)-2-[4-(2-aminoethylamino)butyl]-4-[(R)-2-amino-3-(4-trifluoromethylphenyl)propionyl]-5-isobutylpiperazin-1-yl}-3-(4-trifluoromethyl-phenyl)propan-1-one;(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(4-chlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(4-chlorophenyl)propan-1-one;(R)-2-Amino-1-{(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-[(R)-2-amino-3-(3-trifluoromethylphenyl)propionyl]-2-isobutylpiperazin-1-yl}-3-(3-trifluoromethylphenyl)propan-1-one;1-{(2R, 5S)-5-[4-(2-Aminoethylamino)butyl]-4-[3-(3,4-dichlorophenyl)-propionyl]-2-isobutylpiperazin-1-yl}-3-(3,4-dichlorophenyl)propan-1-one; N¹-(4-{(2S, 5R)-1,4-Bis-[3-(3,4-dichlorophenyl)propyl]-5-isobutylpiperazin-2-yl}butyl)ethane-1,2-diamine; (R)-3-Amino-1-{(2R, 5S)-4-[(R)-3-amino-4-(2,4-dichlorophenyl)butyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-4-(2, 4-dichlorophenyl)butan-1-one;(R)-3-Amino-1-{(2S, 5R)-4-[(R)-3-amino-3-(2,4-dichlorophenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(2, 4-dichlorophenyl)-propan-1-one;(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(4-chloro-2-methylphenyl)-propionyl]2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(4-chloro-2-methyl-phenyl)propan-1-one;(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(2-chloro-4-methylphenyl)-propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(2-chloro-4-methyl-phenyl)propan-1-one;(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(3,4-difluorophenyl)propionyl]-2-[-4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(3 ,4-difluorophenyl)propan-1-one;(R)-2-Amino-1-[(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-4-phenyl-butyryl)-2-isobutylpiperazin-1-yl]-4-phenylbutan-1-one;(R)-2-Amino-1-{(2R,5S)-4-[(R)-2-amino-3-(4-tert-butylphenyl)priopionyl]-5-[4-(2-aminoethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-(4-tert-butylphenyl)propan-1-one;1-{(2R, 5S)-5-[4-(2-Aminoethylamino)butyl]-4-[3-(3,4-dimethylphenyl)-propionyl]-2-isobutylpiperazin-1 -yl}-3-(3,4-dimethylphenyl)propan-1-one; (R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-([1, 3,4]thiadiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2S, 5R)-4-[(R)-2-amino-3-(3,4-dimethylphenyl)propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(3, 4-dimethylphenyl)-propan-1-one;(R)-2-Amino-1-{(2S,5R)-4-[(R)-2-amino-3-(4-chloro-3-methylphenyl)-propionyl]-2-[4-(2-aminoethylamino)butyl]-5-isobutylpiperazin-1-yl}-3-(4-chloro-3-methyl-phenyl)propan-1-one;(R)-2-Amino-1-{(2R,5S)-5[4-(2-aminoethylamino)butyl]-4-[(R)-2-amino-3-(4-methoxyphenyl)propionyl]-2-isobutylpiperazin-1-yl}-3-(4-methoxyphenyl)propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-biphenyl-4-yl-propionyl)-5-[4-(2-amino-ethylamino)butyl]-2-isobutylpiperazin-1-yl}-3-biphenyl-4-yl-propan-1-one;(R)-2-Amino-1-[(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-(3-[1, 2,4]triazol-1-yl-propyl)piperazin-1- yl]-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-([1 , 2,4]triazol-4-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(thiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(5-methylthiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(4-methylthiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(5-methyl-[1,3,4]thiadiazol-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;N-{(R)-2-[(2S,5R)-4-((R)-2-Acetylamino-3-naphthalen-2-yl-propionyl)-5-isobutyl-2-(3-[1,2,4]triazol-1-yl-propyl)piperazin-1-yl]-1-naphthalen-2-ylmethyl-2-oxo-ethyl}-acetamide;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(3-methylisoxazol-5-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(5-methylisoxazol-3-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(pyrimidin-4-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(isoxazol-3-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-2-isobutyl-5-[3-(pyrimidin-2-ylamino)propyl]piperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(R)-2-Amino-1-{(2R,5S)-4-((R)-2-amino-3-naphthalen-2-yl-propionyl)-5-[2-(1H-imidazol-2-yl)ethyl]-2-isobutylpiperazin-1-yl}-3-naphthalen-2-yl-propan-1-one;(S)-2-Amino-1-{(2R, 5S)-4-[(R)-2-amino-3-(2,4-dichlorophenyl)priopionyl]-2-isobutyl-5-[3-([1 , 3,4]thiadiazol-2-ylamino)propyl]piperazin-1-yl}-3-(2,4-dichloro-phenyl)propan-1-one; and (R)-2-Amino-1-[(2R,5S)-5-[4-(2-aminoethylamino)butyl]-4-((R)-2-amino-3-p-tolyl-propionyl)-2-isobutylpiperazin-1-yl]-3-p-tolyl-propan-1-one,or a pharmaceutically acceptable salt thereof.
 10. A pharmaceuticalcomposition comprising a compound as defined in claim 1 or claim 7, or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier.